Retrocomputing

GGLABS Memory Test V0.44

GMT welcome screenGMT (GGLABS Memory Test) is a new developed memory test for vintage computers optimized for speed and coverage. The code is based on the test algorithms described in "Testing Semiconductor Memories: Theory and Practice" by A.J. van de Goor. The program is mostly in C plus small sections in assembly. It is free software and released under the GPL v3 license.

CGA2RGBv2 - Digital RGBI to analog RGB for C128 and IBM PC MDA/CGA/EGA

CGA2RGBThe 80 column output of the Commodore 128 is the same digital RGBI used by the original IBM CGA graphics adapter. Unfortunately nowadays is quite difficult to find a monitor with the suitable RGBI input. The CGA2RGBv2 adapter will convert the TTL RGBI to analog RGB suitable to be connected directly to a 15KHz capable RGB monitor or to the popular Gonbes GBS-8200 VGA converter.

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GZ/80 - Zilog Z80 turbo card for Apple II computers

gz80The Microsoft Softcard was the first card to allow CP/M software to run on the Apple II. It was originally developed to simplify the porting of Microsoft Basic to the Apple II. It turned out to be a great success and at some point in time it was the most popular CP/M platform in use.
This success prompted the development of many compatible cards. Some exact copies, some enhanced or cost reduced. The GZ/80 is a modern implementation of a Softcard compatible card with an additional turbo mode with approximately double the speed of the original card.

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UNICART - Universal Commodore 64/128 Cartridge

ramgsAfter we developed the UNICART/D many customers asked for a more compact version of the cartridge without the pass-through connector. The board uses one standard PLCC32 flash ROM up to 4Mbit. In C64 mode 8K, 16K and 16K Ultimax cartridge modes are supported. In C128 mode both 16K and 32K cartridges are supported.

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F2R16 - Flash based ROM Replacement for Amiga Computers

F2R16The Amiga, like many other computers of the late 80s, uses 16-bit wide mask ROMs to store the machine firmware. Unfortunately, the pinout of these ROMs is incompatible with the JEDEC defined EPROM pinout. Memory manufacturers produced "ROM compatible" EPROMS like the 27C400 to allow development and quick turn manufacturing. These EPROMS are however becoming quite hard to find and still require a UV lamp to erase the chips. F2R16 brings all the benefits of modern flash memory technology to any platform designed to use these obsolete devices.

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GZ/80-A01 - Zilog Z80 turbo card for Apple II computers

A new version of this project is available here

gz80The Microsoft Softcard was the first card to allow CP/M software to run on the Apple II. It was originally developed to simplify the porting of Microsoft Basic to the Apple II. It turned out to be a great success and at some point in time it was the most popular CP/M platform in use.

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T232 - Simple DB9 RS232 monitor and breakout board

T232RS232 monitors are quite common but most of them use the standard good old DB25 connectors. The majority of the RS232 ports in use today however use the smaller DB9 connector. This forces the use chains of adapters to get the commercial monitor/breakout boards working. The GGLABS T232 solves the problem by providing native DB9 connections.

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UNICART/D - Universal Commodore 64/128 Cartridge with Passthrough

ramgsThis cartridge was originally developed to speed up the manufacturing diagnostic of our GRAM and GLINK232 products. Having to load the diagnostic for every board is pretty tedious and time consuming. The UNICART/D allows to have a custom ROM for both C64 and C128 while allowing to still plug in an additional cartridge.

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GZ/80-A00 - Zilog Z80 card for Apple II computers

A new version of this project is available here

ramgsThe Microsoft Softcard was the first card to allow CP/M software to run on the Apple II. It was originally developed to simplify the porting of Microsoft Basic to the Apple II. It turned out to be a great success and at some point in time it was the most popular CP/M platform in use.

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