DIGILAB-R - Vintage Style Digital Trainer

Submitted by GG on Wed, 03/22/2023 - 11:35

SRE DigilabDigital trainers integrate a breadboard with simple I/O and they are a great tool to learn digital circuits. DIGILAB-R is a vintage style digital trainer designed to be compatible with the Scuola Radio Elettra DIGILAB. It can be used to perform all the experiments in the Digital Electronics distance learning course that was popular in the 80's.

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A2SCSI-A02 - Apple II SCSI card clone

Submitted by GG on Fri, 06/24/2022 - 19:34

A new version of this project is available here

A2SCSI FrontThe Apple II SCSI card from 1986 was one of the first interface cards to attach a Hard Disk Drive to the Apple II line of computers. A2SCSI is a clone of the last revision (rev.C) of the card with a few enhancements to improve compatibility with modern SCSI drives.

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M100ROM - 27C256 adapter for Tandy Model 100

Submitted by GG on Tue, 05/17/2022 - 16:47

M10ROMThe Tandy TRS-80 model 100/102 and 200 provide a ROM socket to add built in programs to the machine. To make inserting and replacing the ROM more user friendly the designers choose to use a custom chip socket (Molex series 78805) with 700mils pitch. The Molex carriers that mate with the sockets have been out of production for many years and are nowadays impossible to obtain.

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6502 C Compilers Comparison

Submitted by GG on Sat, 03/12/2022 - 01:11

C6502C is our favorite language as it provides reasonably high level constructs while maintaining very good performance. The majority of the code we write for for both vintage computers and microcontrollers computers is in C. In this article we compare several C compiler for the 6502 to understand the performance and limitations of each.

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SDCC 4.2.0 Released

Submitted by GG on Tue, 03/08/2022 - 13:47

SDCC logoA new release of SDCC, the portable optimizing compiler for STM8, MCS-51, DS390, HC08, S08, Z80, Z180, Rabbit, SM83, eZ80 in Z80 mode, Z80N, TLCS-90, 6502, Padauk and PIC microprocessors is now available. Sources, documentation and binaries for GNU/Linux amd64, Windows amd64, macOS amd64 and Windows x86 are available.

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GS2HD - Apple IIgs RGB to HDTV Component Adapter

Submitted by GG on Thu, 01/13/2022 - 15:25

GS2HD E01The apple IIgs, like many computers from the 80's and early 90's, has a analog RGB output at a 15KHz horizontal frequency (same as NTSC/PAL). The majority of modern monitors and TVs will not sync to anything below 31.5KHz on their VGA input. If you have a TV with a SCART connector it is possible to wire the RGB directly to the TV. Most TVs in USA, however, use the YPbPr component instead of SCART making a direct connection not possible.

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M10MEM - 8KB SRAM Module for Tandy Model 100

Submitted by GG on Wed, 11/03/2021 - 20:02

M10MEMBeing nostalgic for the birth of laptop computers we recently acquired an Olivetti M10. The M10, like many of the KC-85 derivatives like the Tandy TRS-80 Model 100 and the NEC PC8201A, uses custom modules for their system RAM. These modules contained four 2Kx8 SMD SRAMs mounted on a ceramic substrate with a non standard DIP footprint. Needless to say, these modules have become increasingly hard to find.

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