Model 200 RAM: Difference between revisions
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The model 200 comes with 24k built in, and supports up to | The model 200 comes with 24k built in, and supports up to 2 more banks of 24k in the form of ceramic dip modules that plug into the Option RAM #1 & #2 sockets. | ||
=TANDY 26-3866= | |||
The original 24K module was Catalog Number 26-3866.<br> | |||
This is a ceramic DIP carrier with 3 8k sram chips and a 40H138 to decode A13 & A14 into 3 different /CS for the individual SRAM chips. | |||
[[File:TANDY_26-3866_top.jpg|200px|link={{filepath:TANDY_26-3866_top.jpg}}]] | |||
[[File:TANDY_26-3866_bottom.jpg|200px|link={{filepath:TANDY_26-3866_bottom.jpg}}]] | |||
[[File:TANDY_26-3866.svg|frameless|link={{filepath:TANDY_26-3866.svg}}]] | |||
=Modern Replacements= | |||
https://github.com/bkw777/TANDY_200_RAM | |||
<gallery> | |||
File:TANDY_200_RAM.jpg | |||
File:TANDY_200_Dual_RAM.jpg | |||
File:TANDY_200_Dual_RAM_tsop_14mm.jpg | |||
</gallery> | |||
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This module, designed by Steven Adolph, adds both possible optional 24K banks, for a total of 3 banks when installed. | |||
UPDATE: The pcb and parts below have been replaced by this updated design: | |||
*[https://oshpark.com/shared_projects/o1iXGzr1 PCB] | |||
*[http://www.digikey.com/short/jmq927 Parts] | |||
This is parts to build a single board, although OSHPark will ship you 3 boards. You only need one board for one Model 200 computer. If you want to build all 3 boards, then triple all the part quantities on the digikey cart. | |||
OLD VERSION: | |||
*[https://oshpark.com/shared_projects/tepuH2VQ PCB] | *[https://oshpark.com/shared_projects/tepuH2VQ PCB] | ||
*[http://www.digikey.com/short/q71vcp Parts] | *[http://www.digikey.com/short/q71vcp Parts] | ||
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[[File:200_ram_sa_11.jpg|200px]] | [[File:200_ram_sa_11.jpg|200px]] | ||
[[File:200_ram_sa_12.jpg|200px]] | [[File:200_ram_sa_12.jpg|200px]] | ||
[[File:200_ram_sa_13.jpg|200px]] | |||
[https://photos.app.goo.gl/g1G4bo6FbjJSgcqU2 More Pics] | |||
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=More info= | |||
https://archive.org/details/Model_200_Portable_Computer_Service_Manual_19xx_Tandy/page/n75/mode/2up | |||
http://bitchin100.com/wiki/index.php?title=Tandy_200_RAM | http://bitchin100.com/wiki/index.php?title=Tandy_200_RAM | ||
Latest revision as of 19:38, 18 September 2022
The model 200 comes with 24k built in, and supports up to 2 more banks of 24k in the form of ceramic dip modules that plug into the Option RAM #1 & #2 sockets.
TANDY 26-3866
The original 24K module was Catalog Number 26-3866.
This is a ceramic DIP carrier with 3 8k sram chips and a 40H138 to decode A13 & A14 into 3 different /CS for the individual SRAM chips.
Modern Replacements
https://github.com/bkw777/TANDY_200_RAM
More info
https://archive.org/details/Model_200_Portable_Computer_Service_Manual_19xx_Tandy/page/n75/mode/2up