Any cirrus logic gd542x isa/vlb project around?

Check this https://github.com/matt1187/542x_ISA.

Beut, I've got a feeling I've got a salvageable CL chip on an otherwise screwed up NEC powermate motherboard.

silentw wrote on 2025-04-27, 22:09:

Check this https://github.com/matt1187/542x_ISA.

Super cool

Found a ISA CL-5434 Video card project on PCBWay

https://www.pcbway.com/project/shareproject/P … d_7d884912.html

Came across this little Project

https://boginjr.com/it/hw/winchesterduino/
Arduino MFM/RLL hard drive interface

I've spotted this one :

"TefaBlaster" - small MIDI module with WaveBlaster header
https://tefatronix.g6.cz/display.php?page=tef … blaster&lang=en

Compaq Deskpro 386 Modell 2571 & 2572 Memory module replica

https://github.com/matt1187/Let-s-Make-Some-M … -COMPAQ-Edition

I have a number of open source vintage computer projects.

These include CPU drop-in replacement boards for the 6502, 6509, Z80, 8088, 68000, 8051, and a few other random projects.

My Wordpress blog is here: https://microcorelabs.wordpress.com/
GitHub: https://github.com/MicroCoreLabs/Projects

I don't know if this already posted here or not.

https://github.com/slobworks/sisyphus
ESS Solo-1 (ES1938S) based PCI audio card

is there any opensource interpose for am5x86 or am486-100 to convert qfp to pga?

The PC Gameport party is now open source

PC Gameport Party (a pcb breakout of the db15 gameport)

Please add the Picovox project to this list.

It is a device built on top of Raspberry Pi Pico 2 capable of simulating not only Covox, but many more sound devices intended for the LPT port. As of now there is at least partial support for Covox, FTL sound adapter, Stereo-on-1, Disney Sound Source and OPL2LPT, with support for at least CMSLPT and TNDLPT planned.
[..]
Since this device is basically Pico 2 connected to the LPT port, we may add support for more features. Support for (emulating) Digispeech DS311 and DS301 devices, MP3 playback by sending raw data over the LPT port, and even some non-audio features such as printer emulation with saving PDFs.

It's in early stages and no sources or designs have been published yet, but @jansakos has stated that he intends to do so, once some of the basic features have been implemented.

There used to be a project called RTVGA, an 8-bit ISA VGA card built with RTG3105iEH.

The source (presumably KiCad) was in this repository: https://github.com/spark2k06/hardware/ (now gone).

Mentioned in these threads: Re: Arrived ISA 8 bit RTVGA boards and Re: RTVGA 8 bits on PC/104 socket and converter to ISA with MonochromeVGA.

Anyone has archived the source?

ES688F / OPL3 8bit ISA Sound Card
https://github.com/Vakon84/ES688_ISA8

PS2 to com/serial mouse emulator ISA adapter
USB to com/serial mouse emulator ISA adapter

This is promising:

https://maniek86.xyz/projects/m8sbc_486.php

SBC for a 486 with a FPGA chipset implementation... Not yet fully PC compatible but I think it is a good start.

Unfortunatelly with one significant drawback: "The main things missing here are the secondary PIC and DMA. However, based on my tests on this board, many programs can work without these. The missing DMA especially removes sound card support." Maybe he could implement it in FGPA?

oso2k wrote on 2023-03-03, 02:43:

There's 386 replica motherboard project now - https://github.com/Marco-Both/M396F-Replika

My improved open source 386SX/486SLC/486SXLC motherboard based on this design: https://github.com/skiselev/mb386sx-rc2016

BTW, I am curious. I see that several people including Marco Both and matt1187 license their work under the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
What is the rationale there? Is it to avoid some kind of legal issues? (e.g., liability or responsibilities for standard compliance for commercial use?) Or is it just to prevent others from making money using open hardware designs?

I tend to license my open source hardware under CERN Open Hardware strongly reciprocal license (CERN-OHL-S). It does give permission for others to manufacture and sell my designs, but (hopefully) requires the modifications to my designs to be also similarly licensed, and be available in an open-source format.
I don't mind if someone else makes and sells my designs. I am not making money on them anyway. But it does help with the availability.
Of course, even with non-commercial licenses, some people will still manufacture and sell open source hardware projects...

RayeR wrote on 2026-01-12, 17:24:

Unfortunatelly with one significant drawback: "The main things missing here are the secondary PIC and DMA. However, based on my tests on this board, many programs can work without these. The missing DMA especially removes sound card support." Maybe he could implement it in FGPA?

Alternatively, this might be solved in software with a fork of SBEMU that outputs to an LPT DAC (or a similiar direct I/O device that does not require DMA), and emulates only the DAC part of a Sound Blaster, leaving the FM synthesis to be handled by an actual OPL2 or OPL3 device. Since such a hypthetical variant of SBEMU wouldn't have to emulate an OPL2 or OPL3 synthesizer in software, it should (in theory) be fast enough to run on a 486 and add Sound Blaster compatibility to both real mode and protected mode games without any significant CPU overhead.