https://www.cocoacrumbs.com/categories/retro-computing/ Recent content in Retro Computing on Cocoacrumbs Hugo -- gohugo.io en Sun, 06 Oct 2024 00:00:00 +0000 https://www.cocoacrumbs.com/blog/2024-10-06-building-a-nextcube-replica/ Sun, 06 Oct 2024 00:00:00 +0000 https://www.cocoacrumbs.com/blog/2024-10-06-building-a-nextcube-replica/ A few months ago, I stumbled on a NeXT Computer Replica - Raspberry Pi Case from Nina Makes and I printed one of my own but for a Raspberry Pi 4 which required a different back STL file to properly fit. I found this remix here for that. The mini NextCube replica (with a Raspberry PI 4) next to an old 17 inch LCD screen. Using PINN I installed 2 OS’s on the Raspberry PI. https://www.cocoacrumbs.com/blog/2023-04-28-using-zilog-zds-ii-on-linux/ Fri, 28 Apr 2023 00:00:00 +0000 https://www.cocoacrumbs.com/blog/2023-04-28-using-zilog-zds-ii-on-linux/ Picking up my series about the eZ80, “I don’t like Windows.” and “Why do you want to do/know that?” again, I decided to see if I could get the ZDS II running on Linux. This actually turned out to be rather easy, with the right hardware… Installing ZDS II under Wine Since ZDS II is only available for Windows, we need a way to let it run on Linux. Luckily this is rather easy using Wine. https://www.cocoacrumbs.com/blog/2023-01-01-reading-zilogs-lod-file-format/ Sun, 01 Jan 2023 00:00:00 +0000 https://www.cocoacrumbs.com/blog/2023-01-01-reading-zilogs-lod-file-format/ Continuing my series about the eZ80, “I don’t like Windows.” and “Why do you want to do/know that?”, I decided to see if I could make sense of the LOD file format produced by the Zilog tools. Although an Intel HEX file can be produced by the Zilog tools, an Intel HEX file is pure binary and doesn’t contain any debug information. Debug information is present however in Zilog’s LOD file format as a simple HEX dump as in the above picture shows. https://www.cocoacrumbs.com/blog/2022-12-05-experimenting-with-the-ti-cemu-ez80-emulator/ Mon, 05 Dec 2022 00:00:00 +0000 https://www.cocoacrumbs.com/blog/2022-12-05-experimenting-with-the-ti-cemu-ez80-emulator/ Update: Two weeks after posting this blog post, I got a friendly message from Adrien Bertrand. Turns out, there are various projects that use the CEmu core directly. They’re only a bit hard to discover. Two examples are: ez80sf runez80 So, more places to get inspiration from on how to use the CEmu core in your own eZ80 projects. Goals Although the Zilog ZDS II tools do contain a emulator for the eZ80, it only runs on Windows. https://www.cocoacrumbs.com/blog/2021-12-28-experimenting-with-the-llvm-toolchain-for-the-ez80/ Tue, 28 Dec 2021 00:00:00 +0000 https://www.cocoacrumbs.com/blog/2021-12-28-experimenting-with-the-llvm-toolchain-for-the-ez80/ Goals Although the Zilog ZDS II tools do their job, they definitely show their age. The main bottleneck is the C Compiler which is stuck at C89 making compiling modern C code painful if not impossible. Even when modern C code is C89 compliant it’s still no guarantee to compile (a good example is LUA). The C compiler is rather slow as well. A while ago I discovered someone wrote a Z80 family (including ez80) back-end for the LLVM/Clang compiler (for the TI84 Cemu project). https://www.cocoacrumbs.com/blog/2021-10-22-gameduino-3x-on-z20x/ Fri, 22 Oct 2021 00:00:00 +0000 https://www.cocoacrumbs.com/blog/2021-10-22-gameduino-3x-on-z20x/ Having had some hands-on experience now with the SSD1963 display I was somewhat disappointed in the performance. That should not have surprised me since there are a lot of pixels to be moved around with 24 bits colour depth. That’s roughly 1 MByte of memory that needs to be addressed with a humble 8 bits CPU. Even when it would run at 50 MHz, optimized assembly code is required and tricks to get the optimal results. https://www.cocoacrumbs.com/blog/2021-07-02-dec-vt100-enclosure/ Fri, 02 Jul 2021 00:00:00 +0000 https://www.cocoacrumbs.com/blog/2021-07-02-dec-vt100-enclosure/ Now that my terminal works, it’s time to put it into a nice enclosure. And what better enclosure than a replica of the DEC VT100 terminal? After all, this is the terminal that introduced the famous ANSI terminal codes which are still in use today. After a bit of searching I found useful documentation giving me the dimensions of a DEC VT100 terminal. On Aliexpress I found a nice 8" LCD display in a retro 4:3 ratio and with an VGA interface board. https://www.cocoacrumbs.com/blog/2021-07-01-ssd1963-on-z20x/ Thu, 01 Jul 2021 00:00:00 +0000 https://www.cocoacrumbs.com/blog/2021-07-01-ssd1963-on-z20x/ SSD1963 interface code for the eZ80 based Z20X computer A minimal set of routines to initialize the SSD1963 LCD Display Controller in combination with a 7" LCD Display as used by the Z20X computer. Inspiration has been taken from the UTFT Library. Currently, this library allows the following: Initialize the SSD1963 LCD Display Controller for a 7" LCD display. Set front/background colour. Clear the screen (black background). Draw horizontal, vertical lines and rectangles. https://www.cocoacrumbs.com/blog/2021-05-25-hello-world-on-z20x/ Tue, 25 May 2021 00:00:00 +0000 https://www.cocoacrumbs.com/blog/2021-05-25-hello-world-on-z20x/ Intro Since quite some time now, I’ve been intrigued by the Zilog eZ80 which is a successor of the well known Z80. While the eZ80 remains binary compatible with the Z80 it does have some interesting extensions like a flat 24 bits address space (no ugly 64k segments!) allowing to address up to 16 MByte. More info can be found on this Wikipedia page. If you search a bit, then you can quite a few hobby projects using the eZ80. https://www.cocoacrumbs.com/blog/2021-05-20-retro-vga-terminal_part_6/ Thu, 20 May 2021 00:00:00 +0000 https://www.cocoacrumbs.com/blog/2021-05-20-retro-vga-terminal_part_6/ Wrapping up This project is by no means finished (it never is ;-) but so far it works pretty well for me in combination with my RC2014 set up (a SC203 Modular Z180 Computer Kit for RC2014 extended with a Compact Flash Module for CP/M RC2014 Computer). But there is no doubt there are still bugs lingering around. There is no real, solid specification of the ANSI/VT100 escape sequences and unfortunately parts are left open for interpretation. https://www.cocoacrumbs.com/blog/2021-05-19-retro-vga-terminal_part_5/ Wed, 19 May 2021 00:00:00 +0000 https://www.cocoacrumbs.com/blog/2021-05-19-retro-vga-terminal_part_5/ The set-up screen The set-up screen is the only part of the code that is written in C and for this I implemented a very minimal windowing like look and feel (the code is nothing to be proud of though and contains lots of repeated code that could be cleaned up). The set-up screen is activated when you give the terminal the famous three finger salute (i.e. ctrl-alt-del) which brings you with an empty blue screen and a simple menu bar on top. https://www.cocoacrumbs.com/blog/2021-05-18-retro-vga-terminal_part_4/ Tue, 18 May 2021 00:00:00 +0000 https://www.cocoacrumbs.com/blog/2021-05-18-retro-vga-terminal_part_4/ Software Development Writing the code for this terminal really teleported me back to the 1980’s. Luckily with the convenience of quickly erasable NOR Flash memory instead of UV erasable EPROM’s (which would have added 30 minutes or so to every debug cycle). My development cycle starts with writing the assembly/C source code on my Linux PC. Then use the z88dk development kit to generate the binary code. I copy this binary code to a Windows VM to program the NOR Flash using the, probably well known, TL866II plus programmer. https://www.cocoacrumbs.com/blog/2021-05-17-retro-vga-terminal_part_3/ Mon, 17 May 2021 00:00:00 +0000 https://www.cocoacrumbs.com/blog/2021-05-17-retro-vga-terminal_part_3/ Setting up the 6845 Setting up the 6845 involves filling in 16 registers so that the 6845 can generate the correct timing signals for the desired resolution. The available data sheets provide more information on how to calculate the needed values. But since that’s a tedious process, I decided to write a small Python application that could calculate those values for me which you can find below and which was surprisingly accurate. https://www.cocoacrumbs.com/blog/2021-05-16-retro-vga-terminal_part_2/ Sun, 16 May 2021 00:00:00 +0000 https://www.cocoacrumbs.com/blog/2021-05-16-retro-vga-terminal_part_2/ The hardware The design I came up with probably contains few surprises and is inspired by various designs that are floating around on the internet. The complete schematic for the VGA Retro Terminal. Chips used For the TTL chips, the familiar HC or HCT family can be used. There is only one exception. The 74F163 really needs to be from the F family since the HC/HCT version can’t handle the 25. https://www.cocoacrumbs.com/blog/2021-05-15-retro-vga-terminal_part_1/ Sat, 15 May 2021 00:00:00 +0000 https://www.cocoacrumbs.com/blog/2021-05-15-retro-vga-terminal_part_1/ Overview After a long hiatus, which is easily explained as I’ve been working on my most complex project yet. And even more nostalgia I’m afraid… For the last few months I’ve been working on creating an old fashioned video terminal (circa 1980’s) using chips of that era as well (I inherited a ton of TTL chips when my work decided they didn’t need their small electronics lab anymore.). It’s my first digital project in decades and it might still be a bit rough around the edges (my Z80 skills aren’t what they were used to as well I’m afraid). https://www.cocoacrumbs.com/blog/2020-09-04-romwbw-and-linux-how-to-copy-images/ Fri, 04 Sep 2020 00:00:00 +0000 https://www.cocoacrumbs.com/blog/2020-09-04-romwbw-and-linux-how-to-copy-images/ Intro More nostalgia… A few weeks ago I bought the, RC2014 compatible, SC203 Modular Z180 Computer Kit for RC2014 kit on Tindie which uses the Zilog Z180, 512K fast static RAM and 512k ROM (loaded with ROMWBW). To this I added a Compact Flash Module as well for mass storage. With these components it’s possible to create a CP/M compatible system (just add a terminal) running on real hardware of that era. https://www.cocoacrumbs.com/blog/2020-08-25-runcpm-on-linux-and-arduino-due/ Tue, 25 Aug 2020 00:00:00 +0000 https://www.cocoacrumbs.com/blog/2020-08-25-runcpm-on-linux-and-arduino-due/ Intro I got in a nostalgic mood lately, thinking about the long gone days when I made a Z80 slave CPU for my BBC model B computer and ported CP/M 2.2 (and later ZCPR3) to it as well. Me, decades ago, with a BBC model B and home build Z80 slave CPU (grey box at the front) at the CP/M user group stand of the yearly HCC gathering. RetroComputing seems to be on the rise as well and quite some kits are offered to bring back the computer experience of those long gone days.