Retrochallenge 2016/01:
Maze War for Olivetti M10 and NEC PC-8201A

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About this Project

I recently acquired two 1983 portable computers, namely an Olivetti M10 and a NEC PC-8201A. Both are siblings of the Kyocera KC-85 platform, comprising — in alphabetical order — Kyocera's own Kyotronic 85, the NEC PC-8201(A), the Olivetti M10, and, last but not least, the TRS-80 Model 100, with about 6 million sold the most popular of all. (1984 saw the addition of two further models featuring more initial RAM and refined ROMs, the NEC PC-8300 and the TRS-80 Model 102.)

These computers came with a nice version of Microsoft BASIC v.1, a LCD display featuring 8 rows at 40 characters and a graphics resolution of 240 × 64 pixels, and a nice imple­men­tation of serial communications via RS-232C (the NEC PC-8201 adds two more SIO interfaces). So we should be able to network the machines and have a decent game of Maze War running on them, preferably written as a single cross-platform program.

While the two machines, the M10 and the PC-8201A, have much in common and should run at about the same speed, there are also subtle differences. Namely, as of concern for this project, there are differences in the COM-settings, in the communication commands, in the mechanism of machine language/ROM calls (CALL vs. EXEC), and, most importantly, in the graphics support. So we'll have to explore some tricks and work-arounds to get the same approach working for both machines. Support for the Model 100 will be intended, but not tested (I don't have one), the Kyotronic 85 will have to stand aside for lack of documentation (at least in Western/Roman script). (Update: Eventually, the Kyotronic 85 became supported, too, as well as the TRS-80 Model 102 and, probably, the NEC PC-8300.)


The setup: Olivetti M10 and NEC PC-8201A

The setup: Olivetti M10 and NEC PC-8201A, cables, MBA

For this project, we'll use

The Episodes

Including information on the hardware and software of the machines involved, teardown images, the thrills of BASIC-listings and our nifty plans to get there, colorful rants on emulators, German keyboards, and growing upload times, the tale of a small battery wonder, and even more. Eventually, we arrive at a program that is both low-level and does decently (while not rapidly) perform some pseudo-3D rendering in BASIC only, on 5 (or even six) different machines at once (Olivetti M10, NEC PC-8201A, Kyotronic 85, TRS-80 Model 100 and Model 102, and probably the NEC PC-8300, too — 32K of RAM recommended). Not the full game as intended, but some. (Summary added after the fact.)


— Thanks for dropping by and cheers to all others who particpiated in Retrochallenge 2016/01! —

+++ Breaking news: Our humble project was actually picked as one of the winners! :-) +++

Olivetti M10 and NEC PC-8201A

— finis —

— This series is part of Retrochallenge 2016/01. —