Lobsters retrocomputing - 06 Sep 2026

Information about the "Immediate Business Systems" (IBS) and "Radix Micro Devices" FW60 (Field Worker?) very-ruggedised, handheld CP/M computer.

A dump of the ROM hints that it's running Personal CP/M-80.

BDOS function 12 returns the version byte. This one loads 28h:

EE05: 3E 28 LD A,28h ; version 2.8

EE07: C3 4C E3 JP 0E34Ch ; store as BDOS return value

- Hitachi HD64180 CPU

- Hitachi HG61H15 series ASIC ((c) IBS plc)

- NEC D7506G 4-bit microcontroller (for keyboard?)

- 32KB EPROM with Personal CP/M-80 (CP/M 2.2 compatible) plus application software

- Hitachi HD44101 and HD44105 for LCD

- Samsung KM681000BLGI 1Mb/128KB SRAM

The HD64180 (PDF) is an embedded version of the Z80 with MMU. It was licensed back to Zilog as the Z61480 which then became the Z180.

The FW60 I have has nine 1Mb SRAM chips - eight for the 1MB RAM disk and one for the 128KB system RAM. The machine also had a 128KB RAM disk option.

The machine has a three-cell (Sanyo N-600AA) NiCd battery pack (Radix part no. 260525-070-01) rated for 3.6V and 600mAh.

It has a further three batteries installed internally:

- a Saft LS14500 3.6V non-rechargeable lithium-thionyl chloride (Li-SOCl2) battery for retaining the RAM contents over a period of years

- two Sanyo ML2016 3V rechargeable lithium-manganese dioxide (Li-MnO2) cells on the processor board

So far I have dumped the ROM from the Greek-sourced machine I have.

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Original: https://github.com/BrettHallen/Radix_FW60