Apple
A2SCSI - Apple II SCSI card clone
Submitted by GG on Fri, 06/24/2022 - 19:346502 C Compilers Comparison
Submitted by GG on Sat, 03/12/2022 - 01:11C 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.
GS2HD - Apple IIgs RGB to HDTV Component Adapter
Submitted by GG on Thu, 01/13/2022 - 15:25The 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.
RAMGS/4 - 4MB memory expansion for the Apple IIgs
Submitted by GG on Wed, 06/09/2021 - 23:11The apple IIgs is the most advanced computer in the Apple II series. Equipped with a 65c816 8/16-bit CPU with 24-bit address space it could address up to 16MB of memory. The original rom 01 model shipped with 256KB of fast RAM, the revised rom 3 shipped with 1MB (both had an additional 128KB of standard RAM and 64KB of sound RAM). RAMGS/4 is a newly designed 4MB memory expansion card for this great classic computer.
GZ/80S - 20MHz Z-80 PCPI Applicard compatible Apple CP/M card
Submitted by GG on Tue, 04/06/2021 - 14:43The PCPI Appli-Card was the first single board computer style CP/M card for the apple II. It featured a 6MHz Z-80 CPU paired with 64KB of RAM and 2KB of ROM. Thanks to the high clock and zero wait states DRAM accesses the card performed almost 3 times as fast as the Microsoft SoftCard. The GZ/80-B00 is a new implementation of the PCPI card with a 20MHz Z-80 CPU and 512KB of static RAM.
GZ/80 - Zilog Z80 turbo card for Apple II computers
Submitted by GG on Tue, 01/12/2021 - 13:49The 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.
GZ/80S-B00 - 20MHz Z-80 PCPI Applicard compatible Apple CP/M card
Submitted by GG on Thu, 04/02/2020 - 02:19A new version of this project is available here
The PCPI Appli-Card was the first single board computer style CP/M card for the apple II. It featured a 6MHz Z-80 CPU paired with 64KB of RAM and 2KB of ROM. Thanks to the high clock and zero wait states DRAM accesses the card performed almost 3 times as fast as the Microsoft SoftCard. The GZ/80-B00 is a new implementation of the PCPI card with a 20MHz Z-80 CPU and 512KB of static RAM.
GTERM25 - DB25 Active SCSI Terminator with diagnostics LEDs
Submitted by GG on Sun, 02/16/2020 - 15:28Active termination is required to get newer high performance drives working on vintage computers. Unfortunately both the Amiga and older Apple computers use a DB25 SCSI connector which makes finding a suitable terminator quite difficult. GTERM25 solves this problem providing a high performance active terminator with a DB25 connector and SCSI diagnostic LEDs.
GZ/80-A03 - Zilog Z80 turbo card for Apple II computers
Submitted by GG on Thu, 01/30/2020 - 09:57A new version of this project is available here
The 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.