GMT (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.
The NVIDIA Jetson Nano is a great device and its choice of I/O is ideal for user space development. If you are a kernel hacker, however, you will soon feel the need for serial console and a reset button. If you want to hack the bootloader you will also need a recovery button. The Nanobug integrates a UART to USB and buttons into a little board that plugs directly into the nano developer kit.
After 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.
We recently acquired a NVIDIA Jetson Nano developer's kit. It's a great, low power, single board computer with plenty of CPU and GPU performance. The default NVIDIA image is based on Ubuntu 18.04 which is a fine distribution but does not fit nicely At GGLABS all our machines run debian and we started hacking at the nano to make fit our standards.
To continue the tradition we started a few year ago, GGLABS will be at the 2019 Bay Area Maker Faire. The faire will run from May 17th to May 19th. As usual Friday is dedicated to educators and makers while Saturday and Sunday are the general admission days. We will be showing the latest GGLABS creations including the GZ/80 Turbo Z-80 card and the A2SCSI card for apple II. If you plan to attend the faire feel free to stop by and say hi.
The 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.
The GGLABS T232 is very popular for debugging legacy RS-232 connections. In this article we will describe a few debugging tips and show how to emulate some of the common cable configurations.
RS232 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.
This 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.
Both the commodore 64 and the 128 have a software UART implementation that limits the useful speed to 2400 bauds. To work around this limitation Dr. Evil Labs and later CMD produced the SwiftLink232 and Turbo232 cartridges based on the 6551 ACIA chip. Both of these have been out of production for a very long time. GLINK232T is a modern replacement for the CMD Turbo232 allowing the commodore 64/128 to communicate at speeds up to 230400 bauds.