{"id":4581,"date":"2023-02-25T15:50:15","date_gmt":"2023-02-25T15:50:15","guid":{"rendered":"https:\/\/www.petecodes.co.uk\/?p=4581"},"modified":"2023-02-26T21:21:35","modified_gmt":"2023-02-26T21:21:35","slug":"sam-coupe-assembly-language-programming","status":"publish","type":"post","link":"https:\/\/www.petecodes.co.uk\/sam-coupe-assembly-language-programming\/","title":{"rendered":"SAM Coup\u00e8 Assembly Language Programming"},"content":{"rendered":"\n<p>So you\u2019re interested in Assembly Language Programming, and you want to know how to get started down this path on the SAM Coup\u00e9? You\u2019re in the right place! I\u2019ll be taking you through, step by step, in how to get the right tools, get your development tools setup, create some code, get it assembling, test it on an emulator, write your program to disk and debug your code\u2026<\/p>\n\n\n\n<p>Let\u2019s get started\u2026<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">Introduction<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">A Little History<\/h2>\n\n\n\n<p>I\u2019ve recently been reunited with a childhood computer \u2013 An&nbsp;<a href=\"https:\/\/en.wikipedia.org\/wiki\/SAM_Coup%C3%A9\">MGT made Sam Coup\u00e8<\/a>.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><a href=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/SAM_Coup%C3%A9.jpg\"><img decoding=\"async\" src=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/SAM_Coup%C3%A9.jpg\" alt=\"MGT SAM Coupe\" class=\"wp-image-3812\"\/><\/a><\/figure><\/div>\n\n\n<p>I spent long hard summer days working to save up the \u00a3250 for, what was then, a big upgrade from my ZX Spectrum 48k+.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><a href=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/ZX_Spectrum.jpg\"><img decoding=\"async\" src=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/ZX_Spectrum.jpg\" alt=\"Sinclair ZX Spectrum\" class=\"wp-image-3813\"\/><\/a><\/figure><\/div>\n\n\n<p>The Sam Coup\u00e8 was touted as the logical evolution of the ZX Spectrum. Originally developed by Alan Miles and Bruce Gordon in 1989 through their company&nbsp;<a href=\"https:\/\/en.wikipedia.org\/wiki\/Miles_Gordon_Technology\">Miles Gordon Technology or MGT,<\/a>&nbsp;It\u2019s thought roughly 250,000 machines were built in between 1989 and 1994.<\/p>\n\n\n\n<p>I used to write quite a few little programs for this machine back in the day, my favourite of which was an advert for Lemmings which I created in BASIC, and was published in&nbsp;<a href=\"http:\/\/www.worldofsam.org\/node\/752\">Issue 22<\/a>&nbsp;of the perennial Disk based Magazine&nbsp;<a href=\"http:\/\/www.worldofsam.org\/node\/150\">FRED&nbsp;<\/a>by&nbsp;<a href=\"http:\/\/www.worldofsam.org\/node\/106\">Colin MacDonald:<\/a><\/p>\n\n\n\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-4-3 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe title=\"Sam Coupe - Lemmings Advert - Fred 22 (1992)\" width=\"688\" height=\"516\" src=\"https:\/\/www.youtube.com\/embed\/A3YEv5QjOhE?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" allowfullscreen><\/iframe>\n<\/div><\/figure>\n\n\n\n<p>It turned out to be rather prophetic, as it turned out to be FRED Publishing who would go on and bring Lemmings to the SAM Coup\u00e9 some years later. I never made the step up to Assembler programming until much later, when I studied the 6502 at college, using an EMMA 2 Development Board:<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><a href=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/EMMA_2_With_Fault_Board.jpg\"><img decoding=\"async\" src=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/EMMA_2_With_Fault_Board.jpg\" alt=\"EMMA II 6502 Development Board\" class=\"wp-image-3817\"\/><\/a><\/figure><\/div>\n\n\n<p>Since then, I\u2019ve programmed in Assembler on a fair few different platforms, most recently on the&nbsp;<a href=\"http:\/\/www.microchip.com\/design-centers\/8-bit\">Microchip PIC Microcontroller<\/a>.<\/p>\n\n\n\n<p>However, I\u2019ve always yearned to roll back the years and actually learn how to program my old computers, and now that I\u2019ve been reunited with my SAM Coup\u00e9, I thought I\u2019d leap in and give it a go.<\/p>\n\n\n\n<p>As always, it\u2019s the getting started which is the hard part, and there\u2019s very little in the way of detailed curated information for the SAM in this area, which is no surprise given it\u2019s rather niche user base.<\/p>\n\n\n\n<p>But, with the help of Balor Price and Andrew Collier in the excellent&nbsp;<a href=\"https:\/\/www.facebook.com\/groups\/20486797963\/?ref=br_rs\">Sam Coup\u00e9 User Group page on Facebook<\/a>, I was able to get started\u2026 So I thought I\u2019d share my experiences here, in the hope of a) Helping somebody else get started, and b) so that when I come back to this, I\u2019ll be able to get going again myself!<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">Getting Started<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">The Tools<\/h2>\n\n\n\n<p>The best place to get started of course is by aquiring some of the tools required to start Programming and Compiling Sam Coup\u00e9 Code. (We\u2019ll get onto how to use them in a later section!)<\/p>\n\n\n\n<p>I\u2019ll begin with the Editor\u2026 These days I tend to use Microsoft\u2019s Visual Studio Code\u2026This is a really light weight and versatile editor\u2026 You can grab that here;<\/p>\n\n\n\n<p><a href=\"https:\/\/code.visualstudio.com\/\">https:\/\/code.visualstudio.com\/<\/a><\/p>\n\n\n\n<p>If you\u2019d like a little \u201csyntax highlighting\u201d then you can download a nice Z80 Syntax Highlighting extension for Visual Studio Code from here;<\/p>\n\n\n\n<p><a href=\"https:\/\/marketplace.visualstudio.com\/items?itemName=Imanolea.z80-asm\">https:\/\/marketplace.visualstudio.com\/items?itemName=Imanolea.z80-asm<\/a><\/p>\n\n\n\n<p>Next you\u2019ll need an assembler\u2026 There\u2019s an excellent PC Python Based SAM Coup\u00e9 oriented Z80 Assembler from Intensity called PYZ80\u2026 This allows you to Compile Z80 Source code and create SAM Disk Images Directly\u2026<\/p>\n\n\n\n<p>There\u2019s a new version of PYZ80 in a branch by Simon Owen which promises to by Python 3 compatible\u2026 You can get that version here;<\/p>\n\n\n\n<p><a href=\"https:\/\/github.com\/simonowen\/pyz80\">https:\/\/github.com\/simonowen\/pyz80<\/a><\/p>\n\n\n\n<p>PYZ80 doesn\u2019t actually need installing, just unzipping\u2026I unzipped mine into a folder in the root directory\u2026 So something like \u201cc:\\pyz80\\\u201d will do\u2026<\/p>\n\n\n\n<p>PYZ80 is Python Based, so you\u2019ll need to go ahead and download that too:<\/p>\n\n\n\n<p><a href=\"https:\/\/www.python.org\/downloads\/\">https:\/\/www.python.org\/downloads\/<\/a><\/p>\n\n\n\n<p>Next, If you want to make real SAM Disks that Boot on a real SAM, you\u2019ll need to extract the SAMDos 2 file from a SAMDos 2 Disk Image. You can get the SamDos 2 Image from World of Sam here;<\/p>\n\n\n\n<p><a href=\"http:\/\/www.worldofsam.org\/node\/196\">http:\/\/www.worldofsam.org\/node\/196<\/a><\/p>\n\n\n\n<p>You\u2019ll then need a way to extract the SAMDos 2 raw file from the image. For this you can use Andrew Colliers Disk Image Manipulator. You can get that from the Intensity Website at;<\/p>\n\n\n\n<p><a href=\"http:\/\/www.intensity.org.uk\/samcoupe\/download.html\">http:\/\/www.intensity.org.uk\/samcoupe\/download.html<\/a><\/p>\n\n\n\n<p>Before you think about writing Disk Images to actual disks\u2026 You\u2019ll want to test and debug your code\u2026 The fastest way to do this is by running it on an Emulator\u2026 The only one worth considering here is the excellent SimCoupe by Simon Owen\u2026Currently at version 1,1, SimCoupe covers all the various version of the SAM; Memory, Disk Drives, Peripherals etc etc, and even includes a really good debugger too. You can grab a copy from Simon\u2019s GitHub page here;<\/p>\n\n\n\n<p><a href=\"https:\/\/github.com\/simonowen\/simcoupe\/releases\">https:\/\/github.com\/simonowen\/simcoupe\/releases<\/a><\/p>\n\n\n\n<p>If you want to actually write your compiled Disk Images to a real disk for a SAM Coup\u00e9\u2026. Firstly, you\u2019re going to need a suitable PC with a real Floppy Disk Drive\u2026 a USB Floppy drive won\u2019t work here, because the firmware is fixed and they can\u2019t be overridden to write SAM Format Disks. Secondly, you\u2019ll need a handy tool by Simon Owen called SAMDisk, which allows you to Read and Write SAM Format Disk Images from and to actual Disks. You can grab SAMDisk from here;<\/p>\n\n\n\n<p><a href=\"http:\/\/simonowen.com\/samdisk\/#download\">http:\/\/simonowen.com\/samdisk\/sam\/<\/a><\/p>\n\n\n\n<p>Finally\u2026 In order to work around the PC Floppy Driver limitations, you\u2019ll need a Floppy Filter Driver called fdrawcmd.sys\u2026 You can find a copy here;<\/p>\n\n\n\n<p><a href=\"http:\/\/simonowen.com\/fdrawcmd\/\">http:\/\/simonowen.com\/fdrawcmd\/<\/a><\/p>\n\n\n\n<h1 class=\"wp-block-heading\">Getting Started<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">Introducing the code<\/h2>\n\n\n\n<p>Ok\u2026 So, if you\u2019ve got all of the above tools downloaded, extracted and installed\u2026 You should be about ready to go!<\/p>\n\n\n\n<p>Let\u2019s start by opening up Visual Studio Code and writing our first program\u2026. I\u2019ve chosen a program written by&nbsp;<a href=\"http:\/\/www.worldofsam.org\/node\/331\">Steve \u2018Wizard\u2019 Taylor<\/a>&nbsp;and published in&nbsp;<a href=\"http:\/\/www.worldofsam.org\/node\/164\">Issue 6 of Colin MacDonald\u2019s FRED Magaine<\/a>&nbsp;which basically prints an ASCII Character set;<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><a href=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/simc0001.png\"><img decoding=\"async\" src=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/simc0001.png\" alt=\"FRED Magazine Assembly Code Tutorial\" class=\"wp-image-3832\"\/><\/a><\/figure><\/div>\n\n\n<p>With the help of Balor Price and Andrew Collier, I managed to get it to work with PYZ80\u2026 Or, quite possibly, there was a bug in the code which meant it could\u2019ve never run. Either way, you can go ahead and grab a modified and updated version of the code here;<\/p>\n\n\n\n<figure class=\"wp-block-embed is-type-rich is-provider-embed-handler wp-block-embed-embed-handler\"><div class=\"wp-block-embed__wrapper\">\n<span class='coblocks-gist__container' style='pointer-events: none'><script type=\"text\/javascript\" src=\"https:\/\/gist.github.com\/pjgpetecodes\/15c0b63716c00c9acd026ac5665f83a4.js\">\n\/* <![CDATA[ *\/\n\n\/* ]]> *\/\n<\/script>\n<a class=\"gist-block__container\" href=\"https:\/\/gist.github.com\/pjgpetecodes\/15c0b63716c00c9acd026ac5665f83a4\" target=\"_blank\">View this gist on GitHub<\/a><\/span>\n<\/div><\/figure>\n\n\n\n<h1 class=\"wp-block-heading\">Understanding the code<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">The First Loop \u2013 Printing an ASCII Table<\/h2>\n\n\n\n<p>I\u2019m not going to go into masses of deep detail for assembly programming, as there are plenty of resources on the internet to help with that, however, I will break the code down and explain what each section\/line is doing\u2026<\/p>\n\n\n\n<p>On Line 1 we have;<\/p>\n\n\n\n<p><code><strong>autoexec<\/strong><\/code><\/p>\n\n\n\n<p>This piece of code allows our program to automatically start when loaded.<\/p>\n\n\n\n<p>On Line 2 we have;<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code><code><strong>ORG<\/strong>&nbsp;32768<\/code><\/code><\/pre>\n\n\n\n<p>This line puts our code at a specific address in memory. The address 32768 or 8000 in Hex, is a throwback to the Spectrum Memory Map\u2026 In short, the memory was split up into sections, where space below the address 8000 was mapped in conjunction with the ULA, which took precedence, and so called Contended Memory\u2026 So things like driving the screen etc took priority in this area. Everything from 32768 and above was un-contended, so read faster!<\/p>\n\n\n\n<p>Lines 6 and 7 Setup the starting conditions for the loop to Print out an&nbsp;<a href=\"http:\/\/www.asciitable.com\/\">ASCII table<\/a>\u2026 We also encounter our first label\u2026<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code><code>print_test:&nbsp;<strong>LD<\/strong>&nbsp;B, 96<\/code><\/code><\/pre>\n\n\n\n<p>We\u2019re using the B Register as a loop counter here and we want to print 96 characters in OUR ASCII table. The label, at least in this case, is simply so we can give anyone reading the code an idea of our intentions at this point. However, it\u2019s technically useless.<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code><code><strong>LD<\/strong>&nbsp;A, 32<\/code><\/code><\/pre>\n\n\n\n<p>Using the&nbsp;<code>LD<\/code>&nbsp;or&nbsp;<strong>L<\/strong>oa<strong>D<\/strong>&nbsp;instruction, we preload the A Register with 32, which is the first ASCII Character in our ASCII table, and equates to the SPACE character.<\/p>\n\n\n\n<p>On line 9 we start our first loop;<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code><code>loop2:&nbsp;<strong>LD<\/strong>&nbsp;C,A<\/code><\/code><\/pre>\n\n\n\n<p>This is where I\u2019ve needed to make the first change to the original FRED code \u2013 We store the contents of the A register in the C register, so we can retrieve and us it again later\u2026<\/p>\n\n\n\n<p>Next is a call to a predefined SAM Coup\u00e9 Machine Code Subroutine;<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code><code><strong>RST<\/strong>&nbsp;16<\/code><\/code><\/pre>\n\n\n\n<p>The Sam Coup\u00e9 ROM has a selection of predefined routines which we can call from our program which help us speed up development. One of these is described in the&nbsp;<a href=\"http:\/\/sam.speccy.cz\/systech\/sam-coupe_tech-man_v3-0.pdf\">SAM Coup\u00e9 Technical Manual<\/a>&nbsp;as;<\/p>\n\n\n\n<blockquote class=\"wp-block-quote\">\n<p>Print char in \u2018A\u2019 register to current stream. The \u2018K\u2019 and \u2018S\u2019 channels respond to control codes for PEN, PAPER, OVER, INVERSE, FLASH, delete, left, right, up, down, AT, TAB and carriage return<\/p>\n<\/blockquote>\n\n\n\n<p>So, as you can see, on line 9 we\u2019re loading the value of 32 into the A register. The&nbsp;<code><strong>RST<\/strong><\/code>&nbsp;Or&nbsp;<strong>R<\/strong>e<strong>ST<\/strong>art instruction, is very similair to the&nbsp;<code><strong>CALL<\/strong><\/code>&nbsp;instruction. However, it is a far more lightweight but limited instruction, in that it can only call a small selection of predefined ROM addresses, whereas&nbsp;<code><strong>CALL<\/strong><\/code>&nbsp;can call any address in memory.<\/p>\n\n\n\n<p>So here, we\u2019re calling the&nbsp;<code><strong>PRINT<\/strong><\/code>&nbsp;routine at address 16, which takes the contents of the A register and \u201cprints\u201d it to the screen. Actually, the routine will send the contents of the A register to a number of destinations, however we\u2019re using the Screen in this case.<\/p>\n\n\n\n<p>I\u2019ve made the change at Line 9 to cope with the fact that the&nbsp;<code><strong>RST<\/strong>&nbsp;16<\/code>&nbsp;routine will corrupt the contents of the A register. This meant that, where below we\u2019re reusing the A Register, the&nbsp;<code><strong>RST<\/strong>&nbsp;16<\/code>&nbsp;call would leave an incorrect value in the A register, breaking our loop.<\/p>\n\n\n\n<p>So we store the contents of the A register temporarily using the&nbsp;<code><strong>LD<\/strong><\/code>&nbsp;or&nbsp;<strong>L<\/strong>oa<strong>D<\/strong>&nbsp;instruction on Line 9, call&nbsp;<code><strong>RST<\/strong>&nbsp;16<\/code>&nbsp;on Line 10, then on Line 11 we simply restore the previous contents of the A register from our temporary storage in the C Register using the&nbsp;<code><strong>LD<\/strong><\/code>&nbsp;instruction again;<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code><code><strong>LD<\/strong>&nbsp;A,C<\/code>\n<code><strong>RST<\/strong>&nbsp;16<strong>LD<\/strong>&nbsp;C,A<\/code><\/code><\/pre>\n\n\n\n<p>On line 12 we add 1 to the A register. This has the effect of pointing to the next ASCII Character, the first time around the loop this will now be pointing to an exclamation mark character \u201c!\u201d;<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code><code><strong>ADD<\/strong>&nbsp;A,1<\/code><\/code><\/pre>\n\n\n\n<p>On line 13 we\u2019re making use of the&nbsp;<code><strong>CP<\/strong><\/code>&nbsp;or&nbsp;<strong>C<\/strong>om<strong>P<\/strong>are instruction. This instruction compares the given register to the A register. In this case, we\u2019re comparing the B register to the A register. If you remember, we set the B register up with a value of 96 on line 6. This is because 96 is the last ASCII character we want to display in our table\u2026 It corresponds to the back apostrophe \u201c`\u201d character;<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code><code><strong>CP<\/strong>&nbsp;B<\/code><\/code><\/pre>\n\n\n\n<p>On line 14, we are using the&nbsp;<code><strong>JR<\/strong><\/code>&nbsp;instruction. This instruction takes a comparison operator and a jump label. Here, we\u2019re checking to see if the Zero Flag isn\u2019t set, and if it\u2019s not set, we jump to the label&nbsp;<code>loop2<\/code>, which is up there on line 9;<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code><code><strong>JR<\/strong>&nbsp;NZ,loop2<\/code><\/code><\/pre>\n\n\n\n<p>And that\u2019s the first loop complete\u2026<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">Understanding the Code<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">The Second Loop \u2013 Printing a String<\/h2>\n\n\n\n<p>So, with the first loop over, we can now move on to a slightly different printing routine. Whereas above we were simply looping through and printing the next ASCII character, we\u2019ll now print a 20 character long string stored in memory \u2013&nbsp;<em>\u201cHowsaboutis, then!!!\u201d<\/em>.<\/p>\n\n\n\n<p>We store this string right at the end of our program on line 35, with the label text2;<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code><code><strong>DM<\/strong>&nbsp;\"Howsaboutis, then!!!\"<\/code><\/code><\/pre>\n\n\n\n<p>We\u2019ll now be introducing a new concept \u2013 Pointers. In the previous loop, a call to the&nbsp;<code><strong>RST<\/strong>&nbsp;16<\/code>&nbsp;routine would go ahead and print the contents of the A register to the screen. If we want to print a string, we need a way of grabbing each character in our string and sending it to the&nbsp;<code><strong>RST<\/strong>&nbsp;16<\/code>&nbsp;routine.<\/p>\n\n\n\n<p>This is where&nbsp;<a href=\"https:\/\/en.wikipedia.org\/wiki\/Pointer_(computer_programming)\">Pointers<\/a>&nbsp;come in\u2026 Pointers allow our application to grab an item at a location in memory based on a value in a register \u2013 This value is our pointer and points to the position of our string in memory.<\/p>\n\n\n\n<p>In our second loop, we begin on line 18 by setting up our pointer by loading the start of our string into a pair of registers; H and L. These two 8 bit wide registers can be combined together into a single 16bit wide register. We need to do this, as the RAM of the SAM is 16bits wide \u2013 That is, an 8bit register can hold a value from 0 to 255, whereas a 16bit register can hold 0 to 65535;<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code><code><strong>LD<\/strong>&nbsp;HL,text2<\/code><\/code><\/pre>\n\n\n\n<p>We\u2019ve stored our string at a position denoted by the label&nbsp;<code>text2<\/code>, the&nbsp;<code><strong>LD<\/strong><\/code>&nbsp;instruction takes the address of the text2 label and loads it into the H and L register pair. We\u2019ll see later what this looks like when we get onto Debugging.<\/p>\n\n\n\n<p>On line 19 we set up the scope for our loop\u2026 Our string is 20 characters long, so we need to loop through each of the 20 characters and PRINT it to the screen. Again. we use the B register here for our loop, as the A register is used to hold the value to show on the screen;<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code><code><strong>LD<\/strong>&nbsp;B,20<\/code><\/code><\/pre>\n\n\n\n<p>On line 21 we have the start of our loop, and the first time we start utilising the Pointer we set up at Line 18;<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code><code><strong>LD<\/strong>&nbsp;A,(HL)<\/code><\/code><\/pre>\n\n\n\n<p>The line above introduces a new style of instruction, where we\u2019ve wrapped an operand in Parentheses, this denotes to the Assembler that this operand is a Pointer. So we\u2019re saying that we want to&nbsp;<strong>L<\/strong>oa<strong>D<\/strong>&nbsp;a value, pointed to by the HL register pair, into the A register. The first time round this loop, this will the the ASCII character H, or Decimal 72 \/ Hex 48.<\/p>\n\n\n\n<p>Next, on line 22, we have a familiar call to&nbsp;<code><strong>RST<\/strong>&nbsp;16<\/code>, which we know by now, Prints the contents of the A Register to the Screen.<\/p>\n\n\n\n<p>On line 23, we use the&nbsp;<code><strong>INC<\/strong><\/code>&nbsp;or&nbsp;<strong>INC<\/strong>rement instruction, to point the HL register to the next character in our string;<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code><code><strong>INC<\/strong>&nbsp;HL<\/code><\/code><\/pre>\n\n\n\n<p>Next, on line 24, we us the DJNZ or&nbsp;<strong>D<\/strong>ecrement and&nbsp;<strong>J<\/strong>ump if&nbsp;<strong>N<\/strong>ot&nbsp;<strong>Z<\/strong>ero instruction to decrement our Loop Counting B register;<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code><code><strong>DJNZ<\/strong>&nbsp;print_loop<\/code><\/code><\/pre>\n\n\n\n<p>This instruction, decrements the B register, and if the register isn\u2019t Zero, that is, the result of Decrementing the B register doesn\u2019t set the Zero Flag in the processor, then the code should jump to the print_loop label on line 21. Obviously the first 19 times around the B register will be counting down to zero, and only when we\u2019ve printed the final character \u2013 An exclamation mark \u2013 will we exit the loop.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\"><strong>Understanding the code<\/strong><\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">The Final Loop \u2013 Reading the Keyboard<\/h2>\n\n\n\n<p>With the main body of our program complete, we have one final step to take care of\u2026 Running our code at the minute, will happily work without any errors\u2026 The only problem is, once it\u2019s finished showing our ASCII table and our string,it exits right back to BASIC, and both disappear\u2026 Not the best result!<\/p>\n\n\n\n<p>What we need to do is show our ASCII table and string, then wait for the user to hit a key before returning to BASIC.<\/p>\n\n\n\n<p>As I mentioned earlier\u2026 The SAM Coup\u00e9 ROM has got a set of pre-programmed routines which can be accessed by our code. We have access to a routine called&nbsp;<code><strong>JREADKEY<\/strong><\/code>&nbsp;which reads the keyboard, and if a key is pressed, stores the key value in the A register. If no key is pressed, the Z or&nbsp;<strong>Z<\/strong>ero flag is set.<\/p>\n\n\n\n<p>On line 28, we&nbsp;<code><strong>CALL<\/strong><\/code>&nbsp;the address for&nbsp;<code><strong>JREADKEY<\/strong><\/code>&nbsp;which is&nbsp;&amp;0169. You\u2019ll notice that we\u2019re not using&nbsp;<code><strong>RST<\/strong><\/code>&nbsp;here, which is because this routine doesn\u2019t fall under the small remit of routines covered by the&nbsp;<code><strong>RST<\/strong><\/code>&nbsp;instruction;<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code><code>wait_for_key:<strong>&nbsp;CALL<\/strong>&nbsp;&amp;0169<\/code><\/code><\/pre>\n\n\n\n<p>This line forms the start of a loop where we wait for the user to press a key. On line 29 we check the Zero flag, and if it\u2019s set, we simply return to line 28 and check the keyboard again;<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code><code><strong>JR<\/strong>&nbsp;Z,wait_for_key<\/code><\/code><\/pre>\n\n\n\n<p>It should be noted, that as well as the&nbsp;<code><strong>JREADYKEY<\/strong><\/code>&nbsp;routine,we could have also simply used the&nbsp;<code><strong>JWAITKEY<\/strong><\/code>&nbsp;routine. However, I chose&nbsp;<code><strong>JREADYKEY<\/strong><\/code>&nbsp;to demonstrate how we loop to wait for a key press.<\/p>\n\n\n\n<p>Finally, on line 30, we have the&nbsp;<code><strong>RET<\/strong><\/code>&nbsp;or&nbsp;<strong>RET<\/strong>urn instruction. This instruction exits the program and returns us back to the BASIC interpreter;<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code><code><strong>RET<\/strong><\/code><\/code><\/pre>\n\n\n\n<p>And that\u2019s the end of our code\u2026 Once assembled, running this code will produce a result like the following;<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><a href=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/ASCII-Table.png\"><img decoding=\"async\" src=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/ASCII-Table.png\" alt=\"SAM Coupe Assembly Code Output\" class=\"wp-image-3884\"\/><\/a><\/figure><\/div>\n\n\n<p>But, before we get to actually see our program running, we need to assemble it, and convert it into a disk image\u2026<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">Assembling the Code<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">PYZ80<\/h2>\n\n\n\n<p>Ok\u2026 So we\u2019ve completed the code, it\u2019s time to make it into something we can run! The process of turning a raw text Assembly Language file into an executable program is called Assembling. This process converts the individual Mnemonics into Machine Code&nbsp;Opcodes and Operands \u2013 Essentially Binary, which the Z80B processor can run.<\/p>\n\n\n\n<p>The tool we\u2019ll use to assemble our code is&nbsp;<a href=\"https:\/\/github.com\/simonowen\/pyz80\">Simon Owens\u2019 branch of PYZ80<\/a>. PYZ80 as the name suggests, is a Python based Assembler, which allows us to take our code file, add in a DOS image, and produce a SAM Coup\u00e9 compatible Disk image. We\u2019ll go through the steps needed in detail here\u2026<\/p>\n\n\n\n<p>The first thing to do is make sure that you have Python installed \u2013 You can install either version of Python at this point, as Stefan Drissen as kindly updated PYZ80 to be Python 3 compatible.<\/p>\n\n\n\n<p>Once you\u2019ve installed Python, it\u2019s a good idea to check that it\u2019s installed correctly and up and running, the best way to do that is to open up a command prompt and type&nbsp;<code>python<\/code>.If python is installed, you should get something along the lines of;<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><a href=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/Python-Installed.png\"><img decoding=\"async\" src=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/Python-Installed.png\" alt=\"Assembly Code Tools - Python Installed Correctly\" class=\"wp-image-3889\"\/><\/a><\/figure><\/div>\n\n\n<p>You can see above, that I have Python 3.6.2 installed. If you receive an error instead, go and make sure that Python is installed correctly, using a repair install.<\/p>\n\n\n\n<p>Once, you\u2019ve got python installed, download a copy of&nbsp;<a href=\"https:\/\/github.com\/simonowen\/pyz80\">Simon Owens\u2019 branch of PYZ80<\/a>&nbsp;and unzip it to an easy location on your hard drive. I renamed the main directory and chose just d:\\pyz80\u2026<\/p>\n\n\n\n<p>Once you\u2019ve done that, You can copy or move your Source File into the same directory as pyz80\u2026 This isn\u2019t strictly necessary, but just makes like easier when we come to run our commands.<\/p>\n\n\n\n<p>Next , open a command prompt in the pyz80 directory, and we\u2019ll try assembling our code for the first time\u2026. The Assembly process at this stage is rather simple, where we simply type;<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code><code>python pyz80.py helloworld.asm<\/code><\/code><\/pre>\n\n\n\n<p>pyz80 will then Assemble our code and automatically create a SAM Coup\u00e9 Disk Image image for us;<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><a href=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/pyz80-First-Assemble.png\"><img decoding=\"async\" src=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/pyz80-First-Assemble.png\" alt=\"Assembly Code Tools - PYZ80 Assembles Correctly\" class=\"wp-image-3892\"\/><\/a><\/figure><\/div>\n\n\n<p>All being well, you\u2019ll see something similair to what you can see above\u2026 If not, then check what the error message is telling you, and look at the appropriate line in your code.<\/p>\n\n\n\n<p>Our directory now has our brand new Sam Coup\u00e9 Disk Image in it;<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><a href=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/pyz80-Disk-Image.png\"><img decoding=\"async\" src=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/pyz80-Disk-Image.png\" alt=\"Assembly Code Tools - PYZ80 Produced Disk Image\" class=\"wp-image-3893\"\/><\/a><\/figure><\/div>\n\n\n<p>Wahoo\u2026 We\u2019ve just successfully Assembled our SAM Coup\u00e9 source file!<\/p>\n\n\n\n<p>The next step is to try running the code in SimCoupe\u2026 SimCoupe is what is known as an emulator \u2013 A piece of software which, when running, pretends to be the hardware and software of another device. In this case,the original SAM Coup\u00e9.<\/p>\n\n\n\n<p>First, go ahead and download the&nbsp;<a href=\"https:\/\/github.com\/simonowen\/simcoupe\/releases\">latest SimCoupe release from github<\/a>. Extract the zip file to somewhere memorable on your hard drive and run the SimCoupe executable. All being well, you\u2019ll be presented with the familiar Sam Coup\u00e9 Opening Screen;<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><a href=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/SimCoupe-Intro.png\"><img decoding=\"async\" src=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/SimCoupe-Intro.png\" alt=\"Assembly Code Tools - SimCoupe Sam Coupe Start Screen\" class=\"wp-image-3894\"\/><\/a><\/figure><\/div>\n\n\n<p>We can now try opening our newly created Disk Image and seeing if SimCoupe will run it for us\u2026 So, go to File&gt;Open and navigate to your pzy80 directory and open your HellowWorld.dsk file\u2026 All being well, as soon as you finish opening the file, SimCoupe should automatically load your program, and you should see something similair to;<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><a href=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/SimCoupe-Hello-World-First-Run.png\"><img decoding=\"async\" src=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/SimCoupe-Hello-World-First-Run.png\" alt=\"Assembly Code Tools - SimCoupe Program Output\" class=\"wp-image-3895\"\/><\/a><\/figure><\/div>\n\n\n<h1 class=\"wp-block-heading\">Assembling the Code<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">For a real SAM Coup\u00e9<\/h2>\n\n\n\n<p>We now have a program that compiles and runs in SimCoupe! But, what we really want is to be authentic and run our program on a real SAM Coup\u00e9\u2026 There\u2019s a few steps to go through to achieve this\u2026<\/p>\n\n\n\n<p>Firstly, you\u2019ll need a copy of&nbsp;<a href=\"http:\/\/www.intensity.org.uk\/samcoupe\/download.html\">Andrew Colliers Disk Image Manipulator<\/a>\u2026 Download and extract this to a location you can remember on your hard drive.<\/p>\n\n\n\n<p>Next we need to add SAMDOS to our image\u2026 In order to do this, you\u2019ll need to go and grab a&nbsp;<a href=\"http:\/\/www.worldofsam.org\/node\/196\">disk image of SAMDOS 2<\/a>\u2026 Download that and save it to the directory you put the Disk Image Manipulator. It might be worthwhile renaming that file to something easier to type in later, like SAMDOS2.dsk maybe?<\/p>\n\n\n\n<p>What we\u2019re going to do is extract the actual SAMDOS file from our Disk Image. Adding this file to our Assembled Disk Image, will allow the SAM Coup\u00e9 to load our Program.<\/p>\n\n\n\n<p>So, open a command prompt and run dskman32 (No i!)\u2026 You should be presented with a simple interface;<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><a href=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/DiskManipulator-1.png\"><img decoding=\"async\" src=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/DiskManipulator-1.png\" alt=\"Assembly Code Tools - DiskmanDOS Menu\" class=\"wp-image-3899\"\/><\/a><\/figure><\/div>\n\n\n<p>Press the O key on your keyboard, and you\u2019ll be prompted to enter the filename of the Disk Image you want to open. If you renamed your file as I suggested, then type SAMDOS2.dsk here and press enter, after which you should see that the Disk Image has been loaded;<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><a href=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/DiskManipulator-2.png\"><img decoding=\"async\" src=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/DiskManipulator-2.png\" alt=\"Assembly Code Tools - DiskmanDOS SAMDOS2\" class=\"wp-image-3900\"\/><\/a><\/figure><\/div>\n\n\n<p>We can now examine the contents of the loaded Disk by pressing the D key, which should look something similair to;<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><a href=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/DiskManipulator-3.png\"><img decoding=\"async\" src=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/DiskManipulator-3.png\" alt=\"Assembly Code Tools - DiskmanDOS SAMDISK2 Files\" class=\"wp-image-3901\"\/><\/a><\/figure><\/div>\n\n\n<p>The file we want to extract from this disk is the first item listed called \u201csamdos2\u201d. So, if you press L key to \u201cLoad file from .dsk\u201d you\u2019ll be prompted to enter a filename. This is the filename of the file within our Disk Image, so enter \u201csamdos2\u201d, then press return. Next you\u2019ll be prompted to enter a filename to save the samdos2 file as. Enter samdos2.raw here and press return, after which the program will tell us that the file has been saved, along with some details about it;<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><a href=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/DiskManipulator-4.png\"><img decoding=\"async\" src=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/DiskManipulator-4.png\" alt=\"Assembly Code Tools - DiskmanDOS SAMDOS2 Extract File\" class=\"wp-image-3902\"\/><\/a><\/figure><\/div>\n\n\n<p>We can now quit the Disk Manipulator using the Q key. Now that we\u2019re back to the command prompt, if you run the dir command, you should see our new samdos2.raw file;<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><a href=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/DiskManipulator-5.png\"><img decoding=\"async\" src=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/DiskManipulator-5.png\" alt=\"Assembly Code Tools - DiskmanDOS SAMDOS2 File Extracted\" class=\"wp-image-3903\"\/><\/a><\/figure><\/div>\n\n\n<p>Using explorer, copy the samdos2.raw file to your pyz80 directory and open a command prompt there again if you\u2019ve closed that window.<\/p>\n\n\n\n<p>We can now reassemble our source code again, but this time, we can \u201cinclude\u201d the samdos2.raw file with the&nbsp;<code>-I<\/code>&nbsp;switch. So, if you type;<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code><code>python pyz80.py --nozip -I samdos2.raw helloworld.asm<\/code><\/code><\/pre>\n\n\n\n<p>Which should assemble correctly just as before. You might have also noticed that we\u2019ve added a&nbsp;<code>--nozip<\/code>&nbsp;switch. This allows the Disk Manipulator Program to open our disk image.<\/p>\n\n\n\n<p>With that in mind, go ahead and copy our helloworld.dsk file into the DiskmanDOS directory using explorer, and switch back to, or open up a new command window at that location, and run diskman32.exe.<\/p>\n\n\n\n<p>Press the O key and enter \u201chelloworld.dsk\u201d, which should happily load our new Disk Image. Press the D Key, and we should now have the \u201csamdos2,.raw\u201d file and our \u201chelloworld\u201d file;<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><a href=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/DiskManipulator-6.png\"><img decoding=\"async\" src=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/DiskManipulator-6.png\" alt=\"Assembly Code Tools - DiskmanDOS - Full Disk\" class=\"wp-image-3904\"\/><\/a><\/figure><\/div>\n\n\n<p>You can now quit the Disk Manipulator program, and open up SimCoupe again\u2026 Open your new helloworld.dsk Disk Image and make sure it still works!<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">Writing the Image to a real disk<\/h1>\n\n\n\n<p>Ok\u2026 Now it\u2019s time to get serious and try our program out on a real SAM!&nbsp;You\u2019ll need a PC with a Floppy drive for this bit of course\u2026 You won\u2019t be able to use a USB floppy drive, as we\u2019ll be writing a non standard image to the Disk, which USB Floppy Drives won\u2019t let us do. You\u2019ll also need a Dual Density 720Kb Disk\u2026 (Or possibly just tape across the hole on a HD 1.44Mb disk \ud83d\ude09 )<\/p>\n\n\n\n<p>So, fire up your Floppy Drive based PC, and download Simon Owens SAM Disk\u2026. Go ahead and extract that to somewhere memorable\u2026 I just put mine in the root, so c:\\SAMDisk.<\/p>\n\n\n\n<p>Next your going to need a driver so that SAMDisk can control how the floppy drive reads and writes images at a lower level\u2026 For this you\u2019ll need to install&nbsp;<a href=\"http:\/\/simonowen.com\/fdrawcmd\/\">a driver called fdrawcmd.sys<\/a>.<\/p>\n\n\n\n<p>Once that\u2019s installed copy your helloworld.dsk file into your c:\\SAMDisk (or whatever you called it) directory and&nbsp;open a command prompt at that location. running a dir command should show something like;<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><a href=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/Sam-Disk-CMD.png\"><img decoding=\"async\" src=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/Sam-Disk-CMD.png\" alt=\"Assembly Code Tools - SAMDisk Directory\" class=\"wp-image-3906\"\/><\/a><\/figure><\/div>\n\n\n<p>We now need to run SAMDisk and have it write our image to disk. Generally you won\u2019t need any options for this at all, although, if you struggle to get images to work, spend some time looking at Simon Owen\u2019s website, and see if you can figure it out. The command we need to run is simply;<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code><code>samdisk helloworld.dsk a:<\/code><\/code><\/pre>\n\n\n\n<p>Inserting a disk and running this command will write the image sector by sector, head by head to our disk;<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><a href=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/SAMDisk.gif\"><img decoding=\"async\" src=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/SAMDisk.gif\" alt=\"Assembly Code Tools - SAMDisk Writing Animation\" class=\"wp-image-3907\"\/><\/a><\/figure><\/div>\n\n\n<p>The above has been sped up by quite a few times of course, but when it\u2019s complete, and assuming you don\u2019t get a failure with a red warning\u2026 Your disk is ready to pop into your SAM Coup\u00e9 and hit F9!!!<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><a href=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/DiskInSAM.gif\"><img decoding=\"async\" src=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/DiskInSAM.gif\" alt=\"Assembly Code Tools - Our program on a Real Sam Coupe\" class=\"wp-image-3908\"\/><\/a><\/figure><\/div>\n\n\n<h1 class=\"wp-block-heading\">Bonus Section<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">Debugging our code<\/h2>\n\n\n\n<p>Moving on in our path of developing SAM Coup\u00e9 software, we\u2019re likely to write more and more complicated software. Eventually we\u2019ll end up having a problem that we need to diagnose. The easiest way to do this is to use a debugger\u2026 Nicely, SimCoupe has a debugger built in\u2026 So, open up SimCoupe again, and load your helloworld.dsk file.<\/p>\n\n\n\n<p>Our program will be shown\u2026 We can now invoke the debugger\u2026 In version 1.2 of SimCoupe, you can access the Debugger by pressing the \u201c\/\u201d key on your numberpad. If you haven\u2019t got a numberpad on your keyboard, you can either access the debugger from the Tools menu, or download a NumberPad emulator such as\u00a0<a href=\"https:\/\/l.facebook.com\/l.php?u=https%3A%2F%2Fsourceforge.net%2Fprojects%2Fnumpad-emulator%2F%3Fsource%3Dtyp_redirect&amp;h=ATPLqUSOC2OFV_Y1MRmZbL_Drep2hy2NYeDR3Q3za0R39tRJz4cxQxG3LKR6u4YJWS7cgUeOV3uFgLPOxmQlnYyL-LES1_BT1gz2LoV4htWdPqaIl_WnuRF-MNdTgKeJUOY5_4mJsg\">NumPad<\/a>. This will show the SimCoupe Dissasembler;<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><a href=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/SimCoupe-Debugger.png\"><img decoding=\"async\" src=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/SimCoupe-Debugger.png\" alt=\"Assembly Code Tools - SimCoupe Debugger\" class=\"wp-image-3911\"\/><\/a><\/figure><\/div>\n\n\n<p>We now need to find our code. User code is separated into pages of 64k in the SAM Coup\u00e9 Memory. The SAM Coup\u00e9 has two registers which control which page of RAM is active \u2013 The LMPR (<strong>L<\/strong>ow&nbsp;<strong>M<\/strong>emory&nbsp;<strong>P<\/strong>age&nbsp;<strong>R<\/strong>egister) and HMPR (<strong>H<\/strong>igh&nbsp;<strong>M<\/strong>emory&nbsp;<strong>P<\/strong>age&nbsp;<strong>R<\/strong>egister);<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><a href=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/Sam-Coupe-RAM-Pages.png\"><img decoding=\"async\" src=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/Sam-Coupe-RAM-Pages.png\" alt=\"Assembly Code Tools - Sam Coupe RAM Pages\" class=\"wp-image-3912\"\/><\/a><\/figure><\/div>\n\n\n<p>Our code is stored at 32768 if you remember, which is 8000 in hex. So we need to select Section C above. We do this by loading the HMPR register with a 1, which selects the first 64k page of RAM in Section C, which is where our code is. To do this, with the debugger open, press the \u201cH\u201d key and enter a value of \u201c1\u201d followed by pressing Enter.<\/p>\n\n\n\n<p>Next we need to navigate to the start of our code, which resides at address 8000. To do this, press the \u201cA\u201d key and enter a value of 8000, which should show us our code;<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><a href=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/SimCoupe-Debugger-2.png\"><img decoding=\"async\" src=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/SimCoupe-Debugger-2.png\" alt=\"Assembly Code Tools - SimCoupe Debugger - Our Code\" class=\"wp-image-3913\"\/><\/a><\/figure><\/div>\n\n\n<p>You\u2019ll see that the SimCoupe Debugger refers to all values in HEX rather than the Decimal we\u2019re using in our source code. However, you can see our first two lines of code proper beginning at address 8000, which in our code begins at the label print_test;<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code><code><strong>LD<\/strong> B,60<\/code>\n<code><strong>LD<\/strong> A,20<\/code><\/code><\/pre>\n\n\n\n<p>If we\u2019re having trouble with our code, what we ideally want to be able to do is step through each line of code and examine the contents of the various registers. We can do this in the debugger by setting what\u2019s known as a BreakPoint at our first line of code. This has the effect of stopping the execution of our code when the program hits the line with the BreakPoint set on it. To set our BreakPoint double click the top line of code \u2013&nbsp;<code>LD B,60<\/code>. This will turn that line red, indicating the BreakPoint has been set successfully;<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><a href=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/SimCoupe-Debugger-Breakpoint.png\"><img decoding=\"async\" src=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/SimCoupe-Debugger-Breakpoint.png\" alt=\"Assembly Code Tools - SimCoupe Debugger - Breakpoint Set\" class=\"wp-image-3914\"\/><\/a><\/figure><\/div>\n\n\n<p>Now, press the escape key to exit the debugger, and press the F9 key to boot our code back up again, at which point, the debugger should be shown,&nbsp;the code should stop and the line we set our debugger on should be highlighted to indicate that\u2019s where the current execution is;<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><a href=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/SimCoupe-Debugger-Breakpoint-hit.png\"><img decoding=\"async\" src=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/SimCoupe-Debugger-Breakpoint-hit.png\" alt=\"Assembly Code Tools - SimCoupe Debugger - Start of our code\" class=\"wp-image-3915\"\/><\/a><\/figure><\/div>\n\n\n<p>You\u2019ll notice that the code in the debugger window is missing all of course labels however. This is common in debuggers, as the assembled file we created normally has no way of conveying our labels to the Debugger, instead, all the labels are replaced with their numeric equivalents. While functional, this doesn\u2019t make for a nice reading experience\u2026 So, with a tip from Simon Owen, we can slightly modify our PYZ80 assemble command to create what\u2019s known as a \u201cmap\u201d file. This file, when used with the SimCoupe debugger, allows the debugger to convert the assembled numbers in the source code back into their text equivalents\u2026 Very neat!<\/p>\n\n\n\n<p>So, to create our \u201cmap\u201d file, we use the following command for PYZ80;<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code><code>python pyz80.py --nozip --mapfile=helloworld.map -I samdos2.raw helloworld.asm<\/code><\/code><\/pre>\n\n\n\n<p>Once you\u2019ve created a new version of the HelloWorld.dsk file, reset SimCoupe, and reload your disk. Follow the same steps as detailed above to set the debugger up and set a BreakPoint. This time when your code breaks, you should see a nicely annotated version instead;<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><a href=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/SimCoupe-Debugger-Breakpoint-hit-Map-File.png\"><img decoding=\"async\" src=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/SimCoupe-Debugger-Breakpoint-hit-Map-File.png\" alt=\"\" class=\"wp-image-3930\"\/><\/a><\/figure><\/div>\n\n\n<p>We can now step through our code using the Number-Pad 8 key. This has the effect of stepping over each instruction, meaning that any execution will simply step over any CALL or RST instructions, rather than stepping into each routine separately, which just simplifies this demonstration somewhat.<\/p>\n\n\n\n<p>As I mentioned earlier, while I was getting started with this code, which as I mentioned was taken from FRED Magazine Issue 6, I found that it didn\u2019t work correctly for some reason. The issue was introduced upon a call to&nbsp;<code>RST 16<\/code>&nbsp;(<code>RST 10<\/code>&nbsp;in the debugger). We can actually see this issue in action if we step through the code past the&nbsp;<code>RST 16<\/code>&nbsp;instruction;<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><a href=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/SimCoupe-Debugger-Step-Over.gif\"><img decoding=\"async\" src=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/SimCoupe-Debugger-Step-Over.gif\" alt=\"Assembly Code Tools - SimCoupe Debugger - Stepping Over\" class=\"wp-image-3916\"\/><\/a><\/figure><\/div>\n\n\n<p>You\u2019ll see, at 8002 we load the value of 20 into the A register. You can see the Value of the A register at the top right section, combined with the F register, being set to 203B after the instruction at 8002 has been executed \u2013 The A register has a value of 20, the F register has a value of 3B.<\/p>\n\n\n\n<p>After storing the A register in the C register at 8004, we have the&nbsp;<code>RST 10<\/code>&nbsp;call. After we\u2019ve returned from the&nbsp;<code>RST 10<\/code>&nbsp;call, you can see that the Value of the A Register has changed from 20 to 00. This had the effect of causing our loop to, well, loop forever, show a page full of \u201c?\u201d symbols, and eventually crash out.<\/p>\n\n\n\n<p>As a result, I added the lines which store and retrieve the A register in the C register, which cures the problem nicely.<\/p>\n\n\n\n<p>You can carry on stepping through the code and examine how the register change, or press the escape key, and the program will run to it\u2019s end again.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">In Conclusion<\/h1>\n\n\n\n<p>To wrap up then\u2026 You\u2019ve learnt how to;<\/p>\n\n\n\n<ul>\n<li>Setup your development environment for SAM Coup\u00e9 Assembly Language Development, including the installation and configuration of various tools.<\/li>\n\n\n\n<li>Create some relevant application source code, including how it all hangs together.<\/li>\n\n\n\n<li>Assemble the source code into a disk image using PYZ80.<\/li>\n\n\n\n<li>Run your disk Image on the SimCoupe Emulator<\/li>\n\n\n\n<li>Extract Files from an existing Disk Image using DiskmanDOS<\/li>\n\n\n\n<li>Add Files into a Disk Image which assembling using PYZ80.<\/li>\n\n\n\n<li>Copy Disk Images to an actual Disk Using SAMDisk and run them on a real SAM Coup\u00e9<\/li>\n\n\n\n<li>Debug code using SimCoupe.<\/li>\n<\/ul>\n\n\n\n<p>If you\u2019d like a copy of the finished Disk Image, feel free to&nbsp;<a href=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/helloworld.zip\">grab a copy here<\/a>!<\/p>\n\n\n\n<p>I really hope that this has helped you get started on your journey to creating some amazing software for the SAM Coup\u00e9!<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><a href=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/Sam_the_robot.png\"><img decoding=\"async\" src=\"https:\/\/pjgcreations.co.uk\/wp-content\/uploads\/2017\/09\/Sam_the_robot.png\" alt=\"Sam Coupe - Sam the Robot\" class=\"wp-image-3918\"\/><\/a><\/figure><\/div>","protected":false},"excerpt":{"rendered":"<p>So you\u2019re interested in Assembly Language Programming, and you want to know how to get started down this path on&hellip;<\/p>\n","protected":false},"author":1,"featured_media":4583,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_coblocks_attr":"","_coblocks_dimensions":"","_coblocks_responsive_height":"","_coblocks_accordion_ie_support":"","_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[61,102,103],"tags":[149,150,148,147],"acf":[],"aioseo_notices":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v22.3 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>SAM Coup\u00e8 Assembly Language Programming - Pete Codes<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.petecodes.co.uk\/sam-coupe-assembly-language-programming\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"SAM Coup\u00e8 Assembly Language Programming - Pete Codes\" \/>\n<meta property=\"og:description\" content=\"So you\u2019re interested in Assembly Language Programming, and you want to know how to get started down this path on&hellip;\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.petecodes.co.uk\/sam-coupe-assembly-language-programming\/\" \/>\n<meta property=\"og:site_name\" content=\"Pete Codes\" \/>\n<meta property=\"article:published_time\" content=\"2023-02-25T15:50:15+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2023-02-26T21:21:35+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/www.petecodes.co.uk\/wp-content\/uploads\/2023\/02\/samlogo_8aa356177db71c69d3337c8c7f9300b0.png\" \/>\n\t<meta property=\"og:image:width\" content=\"524\" \/>\n\t<meta property=\"og:image:height\" content=\"132\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/png\" \/>\n<meta name=\"author\" content=\"PeteCodes\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"PeteCodes\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"29 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\/\/www.petecodes.co.uk\/sam-coupe-assembly-language-programming\/#article\",\"isPartOf\":{\"@id\":\"https:\/\/www.petecodes.co.uk\/sam-coupe-assembly-language-programming\/\"},\"author\":{\"name\":\"PeteCodes\",\"@id\":\"https:\/\/www.petecodes.co.uk\/#\/schema\/person\/c2f636f242b064676ae61ed0022b32e7\"},\"headline\":\"SAM Coup\u00e8 Assembly Language Programming\",\"datePublished\":\"2023-02-25T15:50:15+00:00\",\"dateModified\":\"2023-02-26T21:21:35+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/www.petecodes.co.uk\/sam-coupe-assembly-language-programming\/\"},\"wordCount\":5310,\"publisher\":{\"@id\":\"https:\/\/www.petecodes.co.uk\/#organization\"},\"image\":{\"@id\":\"https:\/\/www.petecodes.co.uk\/sam-coupe-assembly-language-programming\/#primaryimage\"},\"thumbnailUrl\":\"https:\/\/www.petecodes.co.uk\/wp-content\/uploads\/2023\/02\/samlogo_8aa356177db71c69d3337c8c7f9300b0.png\",\"keywords\":[\"Assembler\",\"Assembly Language.\",\"Retro\",\"SAM Coupe\"],\"articleSection\":[\"Assembly Programming\",\"Retro\",\"SAM Coupe\"],\"inLanguage\":\"en-US\"},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.petecodes.co.uk\/sam-coupe-assembly-language-programming\/\",\"url\":\"https:\/\/www.petecodes.co.uk\/sam-coupe-assembly-language-programming\/\",\"name\":\"SAM Coup\u00e8 Assembly Language Programming - Pete Codes\",\"isPartOf\":{\"@id\":\"https:\/\/www.petecodes.co.uk\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/www.petecodes.co.uk\/sam-coupe-assembly-language-programming\/#primaryimage\"},\"image\":{\"@id\":\"https:\/\/www.petecodes.co.uk\/sam-coupe-assembly-language-programming\/#primaryimage\"},\"thumbnailUrl\":\"https:\/\/www.petecodes.co.uk\/wp-content\/uploads\/2023\/02\/samlogo_8aa356177db71c69d3337c8c7f9300b0.png\",\"datePublished\":\"2023-02-25T15:50:15+00:00\",\"dateModified\":\"2023-02-26T21:21:35+00:00\",\"breadcrumb\":{\"@id\":\"https:\/\/www.petecodes.co.uk\/sam-coupe-assembly-language-programming\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/www.petecodes.co.uk\/sam-coupe-assembly-language-programming\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/www.petecodes.co.uk\/sam-coupe-assembly-language-programming\/#primaryimage\",\"url\":\"https:\/\/www.petecodes.co.uk\/wp-content\/uploads\/2023\/02\/samlogo_8aa356177db71c69d3337c8c7f9300b0.png\",\"contentUrl\":\"https:\/\/www.petecodes.co.uk\/wp-content\/uploads\/2023\/02\/samlogo_8aa356177db71c69d3337c8c7f9300b0.png\",\"width\":524,\"height\":132},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/www.petecodes.co.uk\/sam-coupe-assembly-language-programming\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/www.petecodes.co.uk\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"SAM Coup\u00e8 Assembly Language Programming\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.petecodes.co.uk\/#website\",\"url\":\"https:\/\/www.petecodes.co.uk\/\",\"name\":\"Pete Codes\",\"description\":\"Pete Gallagher - Developer and Public Speaker\",\"publisher\":{\"@id\":\"https:\/\/www.petecodes.co.uk\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/www.petecodes.co.uk\/?s={search_term_string}\"},\"query-input\":\"required name=search_term_string\"}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\/\/www.petecodes.co.uk\/#organization\",\"name\":\"Pete Codes\",\"url\":\"https:\/\/www.petecodes.co.uk\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/www.petecodes.co.uk\/#\/schema\/logo\/image\/\",\"url\":\"https:\/\/www.petecodes.co.uk\/wp-content\/uploads\/2020\/06\/Logo-Small-Optimised.png\",\"contentUrl\":\"https:\/\/www.petecodes.co.uk\/wp-content\/uploads\/2020\/06\/Logo-Small-Optimised.png\",\"width\":189,\"height\":100,\"caption\":\"Pete Codes\"},\"image\":{\"@id\":\"https:\/\/www.petecodes.co.uk\/#\/schema\/logo\/image\/\"}},{\"@type\":\"Person\",\"@id\":\"https:\/\/www.petecodes.co.uk\/#\/schema\/person\/c2f636f242b064676ae61ed0022b32e7\",\"name\":\"PeteCodes\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/www.petecodes.co.uk\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/secure.gravatar.com\/avatar\/969dc1e441e755dd7d1f90da569dc913?s=96&d=mm&r=g\",\"contentUrl\":\"https:\/\/secure.gravatar.com\/avatar\/969dc1e441e755dd7d1f90da569dc913?s=96&d=mm&r=g\",\"caption\":\"PeteCodes\"},\"sameAs\":[\"https:\/\/wordpress-634681-2064240.cloudwaysapps.com\"],\"url\":\"https:\/\/www.petecodes.co.uk\/author\/admin\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"SAM Coup\u00e8 Assembly Language Programming - Pete Codes","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.petecodes.co.uk\/sam-coupe-assembly-language-programming\/","og_locale":"en_US","og_type":"article","og_title":"SAM Coup\u00e8 Assembly Language Programming - Pete Codes","og_description":"So you\u2019re interested in Assembly Language Programming, and you want to know how to get started down this path on&hellip;","og_url":"https:\/\/www.petecodes.co.uk\/sam-coupe-assembly-language-programming\/","og_site_name":"Pete Codes","article_published_time":"2023-02-25T15:50:15+00:00","article_modified_time":"2023-02-26T21:21:35+00:00","og_image":[{"width":524,"height":132,"url":"https:\/\/www.petecodes.co.uk\/wp-content\/uploads\/2023\/02\/samlogo_8aa356177db71c69d3337c8c7f9300b0.png","type":"image\/png"}],"author":"PeteCodes","twitter_card":"summary_large_image","twitter_misc":{"Written by":"PeteCodes","Est. reading time":"29 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/www.petecodes.co.uk\/sam-coupe-assembly-language-programming\/#article","isPartOf":{"@id":"https:\/\/www.petecodes.co.uk\/sam-coupe-assembly-language-programming\/"},"author":{"name":"PeteCodes","@id":"https:\/\/www.petecodes.co.uk\/#\/schema\/person\/c2f636f242b064676ae61ed0022b32e7"},"headline":"SAM Coup\u00e8 Assembly Language Programming","datePublished":"2023-02-25T15:50:15+00:00","dateModified":"2023-02-26T21:21:35+00:00","mainEntityOfPage":{"@id":"https:\/\/www.petecodes.co.uk\/sam-coupe-assembly-language-programming\/"},"wordCount":5310,"publisher":{"@id":"https:\/\/www.petecodes.co.uk\/#organization"},"image":{"@id":"https:\/\/www.petecodes.co.uk\/sam-coupe-assembly-language-programming\/#primaryimage"},"thumbnailUrl":"https:\/\/www.petecodes.co.uk\/wp-content\/uploads\/2023\/02\/samlogo_8aa356177db71c69d3337c8c7f9300b0.png","keywords":["Assembler","Assembly Language.","Retro","SAM Coupe"],"articleSection":["Assembly Programming","Retro","SAM Coupe"],"inLanguage":"en-US"},{"@type":"WebPage","@id":"https:\/\/www.petecodes.co.uk\/sam-coupe-assembly-language-programming\/","url":"https:\/\/www.petecodes.co.uk\/sam-coupe-assembly-language-programming\/","name":"SAM Coup\u00e8 Assembly Language Programming - Pete Codes","isPartOf":{"@id":"https:\/\/www.petecodes.co.uk\/#website"},"primaryImageOfPage":{"@id":"https:\/\/www.petecodes.co.uk\/sam-coupe-assembly-language-programming\/#primaryimage"},"image":{"@id":"https:\/\/www.petecodes.co.uk\/sam-coupe-assembly-language-programming\/#primaryimage"},"thumbnailUrl":"https:\/\/www.petecodes.co.uk\/wp-content\/uploads\/2023\/02\/samlogo_8aa356177db71c69d3337c8c7f9300b0.png","datePublished":"2023-02-25T15:50:15+00:00","dateModified":"2023-02-26T21:21:35+00:00","breadcrumb":{"@id":"https:\/\/www.petecodes.co.uk\/sam-coupe-assembly-language-programming\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.petecodes.co.uk\/sam-coupe-assembly-language-programming\/"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.petecodes.co.uk\/sam-coupe-assembly-language-programming\/#primaryimage","url":"https:\/\/www.petecodes.co.uk\/wp-content\/uploads\/2023\/02\/samlogo_8aa356177db71c69d3337c8c7f9300b0.png","contentUrl":"https:\/\/www.petecodes.co.uk\/wp-content\/uploads\/2023\/02\/samlogo_8aa356177db71c69d3337c8c7f9300b0.png","width":524,"height":132},{"@type":"BreadcrumbList","@id":"https:\/\/www.petecodes.co.uk\/sam-coupe-assembly-language-programming\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.petecodes.co.uk\/"},{"@type":"ListItem","position":2,"name":"SAM Coup\u00e8 Assembly Language Programming"}]},{"@type":"WebSite","@id":"https:\/\/www.petecodes.co.uk\/#website","url":"https:\/\/www.petecodes.co.uk\/","name":"Pete Codes","description":"Pete Gallagher - Developer and Public Speaker","publisher":{"@id":"https:\/\/www.petecodes.co.uk\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.petecodes.co.uk\/?s={search_term_string}"},"query-input":"required name=search_term_string"}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/www.petecodes.co.uk\/#organization","name":"Pete Codes","url":"https:\/\/www.petecodes.co.uk\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.petecodes.co.uk\/#\/schema\/logo\/image\/","url":"https:\/\/www.petecodes.co.uk\/wp-content\/uploads\/2020\/06\/Logo-Small-Optimised.png","contentUrl":"https:\/\/www.petecodes.co.uk\/wp-content\/uploads\/2020\/06\/Logo-Small-Optimised.png","width":189,"height":100,"caption":"Pete Codes"},"image":{"@id":"https:\/\/www.petecodes.co.uk\/#\/schema\/logo\/image\/"}},{"@type":"Person","@id":"https:\/\/www.petecodes.co.uk\/#\/schema\/person\/c2f636f242b064676ae61ed0022b32e7","name":"PeteCodes","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.petecodes.co.uk\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/969dc1e441e755dd7d1f90da569dc913?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/969dc1e441e755dd7d1f90da569dc913?s=96&d=mm&r=g","caption":"PeteCodes"},"sameAs":["https:\/\/wordpress-634681-2064240.cloudwaysapps.com"],"url":"https:\/\/www.petecodes.co.uk\/author\/admin\/"}]}},"_links":{"self":[{"href":"https:\/\/www.petecodes.co.uk\/wp-json\/wp\/v2\/posts\/4581"}],"collection":[{"href":"https:\/\/www.petecodes.co.uk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.petecodes.co.uk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.petecodes.co.uk\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.petecodes.co.uk\/wp-json\/wp\/v2\/comments?post=4581"}],"version-history":[{"count":11,"href":"https:\/\/www.petecodes.co.uk\/wp-json\/wp\/v2\/posts\/4581\/revisions"}],"predecessor-version":[{"id":4644,"href":"https:\/\/www.petecodes.co.uk\/wp-json\/wp\/v2\/posts\/4581\/revisions\/4644"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.petecodes.co.uk\/wp-json\/wp\/v2\/media\/4583"}],"wp:attachment":[{"href":"https:\/\/www.petecodes.co.uk\/wp-json\/wp\/v2\/media?parent=4581"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.petecodes.co.uk\/wp-json\/wp\/v2\/categories?post=4581"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.petecodes.co.uk\/wp-json\/wp\/v2\/tags?post=4581"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}