The 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.
GGLABS started lending on Kiva back in 2016 and we are proud to announce that we have just made our 400th loan for a grand total of $10,000 of loaned funds. We love to support entrepreneurs and small businesses around the world to improve their lives. During the years we have supported people from 66 different countries.
C 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.
A 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.
The 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.
Recently we have been working with the SDCC team to include 6502 support in the next release of SDCC. The port is largely based on the excellent work from Steve Hugg at 8-bit workshop. The port passes all the tests in the regression suite and it will be included in the upcoming 4.2.0 release.
Being 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.
A fun way to introduce coding to kids is game development. Vintage machines are ideal to introduce many low level concepts without the complexity or the abstraction of modern, more powerful systems. The game is a classic vertical catch game featuring characters from Hayao Miyazaki's movie "My neighbor Totoro". The goal is to catch the required number of acorns before the time expires.