Model and ROM information

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Information regarding Model type, PCB code, ROM marking, ROM version and checksum is captured here. S. Adolph

  Note: I'll try to keep this list updated.  If anyone has comments or corrections to this please let me know.

What Kind of Model 100 or Tandy 102 do You Have?

Model 100

The first M100s were released with a custom ROM pinout, in agreement with the published schematic. Over time, Radio Shack changed the design to use standard 27C256 compable ROMs. Both variants use essentially the same ROM code. Clearly the schematic for these later variants was different due to the ROM pinout.

Later, versions of the M100 were produced for UK and EU markets. These M100 appear to use 27C256 compatible ROMs, but the ROM code differs from the USA version. The schematic for these versions had changes as the UK M100 had no modem function, and the EU version had a different modem.

Tandy 102

Tandy introduced the 102 from the beginning using a 27C256 compatible ROM. There is a published schematic available. the T102 main ROM had a few improvements and bug fixes compared to the standard M100 main ROM.

Later, versions of the T102 were produced for UK and EU markets. The ROM code again differs from the USA version.

Model Type Information

You can tell these variants apart by observing the presence of the modem, and by looking at the PCB itself. The ROMs will have a unique marking, as does the PCB. In some cases the Tandy product number is different as well. This information is captured in the below table.


M100

Variant Product number PCB code ROM marking ROM checksum stock/y2k ROM image PCB image Note
Early USA 26-3801/3802 PLX110CH1X LH535618 A2CC/(A2D4) m100 This is the usual M100
Late USA 26-(3801)/3802 PLX110EH1X 3256C07-3J1 A2CC/A2D4 same as above Later version
EU 26-(3801)/3802 ?? ?? (A8B7)/A8AF M100rom-e_Y2K Different modem
UK 26-(3801)/3802 PLX120CH1X 3256E30-4C3 EEA4 m100UK_nomodem no modem, BCR, similar to KC-85
UK 26-3801/3802 PLX120BH1X 3256E30-4F3 ?? ?? no modem, BCR, similar to KC-85
UK 26-3801/3802 PLX120BH1X 3256C05-3E1 F0BF sklm100rom no modem, BCR, similar to KC-85
USA 26-3802B PLX120CH1X 3256E30-4D3 A8B7/(A8AF) M100_3802B no modem, BCR, similar to KC-85

T102

Variant Product number PCB code ROM marking ROM checksum stock/y2k ROM image PCB image Note
USA 26-3803 PLX144FH1X M53256-02 A8CA/A8C2 t102_rom This is the usual T102
EU 26-3803 PPPCG2007A*01 PB INT B20F T102_EU_modem Different modem, QWERTY
UK 26-3803 ?? ?? XXXX binary file no modem