One of the early Microsoft 6502 Basic versions, made for the SYM-1.
Two versions were made. The first came as two 4K ROMS, V1.1 as one 8K ROM. ROM ID BAS 023-0025A.
The tri-goniometric functions, an option at startup are documented in the Basic manual as hex dump or on page 27 in the Technotes
There were two versions of the BASIC ROMs available.
- A two ROM set (part numbers 02-0019-01 and 02-0020-1). These went into sockets U21 and U22 respectively.
- A single ROM (part number 02-0058 A/B). This went into socket U21. It’s 8K and it’s position dependent. It fits in from $C000 to $DFFF.
The 8k Basic has tokens but no code for the trig functions. There’s an application note which invites you to type in the hex and save to tape the approx 512 extra bytes needed. See page 27 of the tech notes.
The 1981 manual shows the correct jumpers for an 8K ROM in U21. The 1978 manual shows the correct jumpers for two 4K ROMs in U21 and U22
ROM binaries
BXT_1200 is just 1285 useful bytes, and then filled with FF. It contains the strings PERFECT MATCH!, COMPARE ERROR AT, CHECK SUM ERROR! and INVALID DELETE RANGE!
BXT_0200 is a full 4k bytes, and contains these strings:
FOUND LOADING SEARCHING FOR SAVING CALL STIME EDIT PAGE TRACE CHAIN EXEC PAGE EXTENDED SYM-BASIC BY JOHN W. BROWN COPYRIGHT (C) 1980 SATURN SOFTWARE LIMITED
SYM-1 monitor
The SYM-1 monitor, Supermon, is described in the Reference manual
Written by Manny Lomas, of TIM and RAP fame.
Two versions of the monitor were shipped, Version 1.0 and Version 1.1.
Version SY1.1, the second release of Supermon, is described in a separate manual.
The ROM contains Supermon, the machine monitor, the audio cassette functions and the boot ROM function (vectors and such are cleverly loaded into RAM by some hardware tricks with protected RAM at upper memory.
MOD-68, MOD-69, SYM-1/68, SYM-1/69
The MOD-69 and MOD-68 replace the 6502 with a Motorola 6809 or 6802 CPU on an adaptor board and the Monitor is replaced with a new ROM with a new Supermon.
Scans from Synertek Products Guide.
There were also SYM-1’s available with the Motorola processor 6802 : SYM-1/68 and 6809: SYM-1/69.
A Dutch company, producer of many 6502 and more industrial hardware, BEM was the name one of their product lines.
Brutech Electronics Microsytems – B.E.M
Gebroeders Bruyn, Vinkeveen. Small company, custom made electronics and standard microprocessor boards and systems aimed at industry and hobbyist.
During my years with Radio Bulletin we often worked with Brutech, and I visisted their office/manufacturing plant in Vinkeveen several times. The BEM-bus became the standard bus for expansion at Radio Bulletin after the first BEM-1 card was connected to the KIM-1 by Dick de Boer. Brutech specialized in the beginning on the KIM-1/VIM/SYM-1 expansion cards, later on they made their own CPU cards and besides the 6502 CPUs like the 6809 were available.
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BEM-1 card, as used in the KIM memory expansion article November 1977 |
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The BEM bus |
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Brutech sold the VIM-1 and SYM-1, with their cards as expansions.
Review in Radio Bulletin November 1978 |
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Brutech sold also the PC100, the Siemens OEM version of the AIM 65. Again the expansions could be used, same bus.
Review in Radio Bulletin August 1980 |
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The AIM 65 and KTM-2 packaged as the Samson system,. the BEM-4 memory card, the SYMP universal programmer.
Review in Radio Bulletin November 1980 |
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BEM RTC1 card, advert in the RB CB Special 1980 |
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BEM-Impact 1000, a BEM-bus based development system, review in Radio Bulletin Oktober 1980 |
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BEM Eurocard system, article by C.J. Bruyn, on the BEM bus, BEM-MON-1 (a TIM 6530 004 system!) and other cards |
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Micro-gebeuren november 1977, BEM-1, other BEM cards |
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Micro-gebeuren April 1980, BEM-PSIO-1 USART card, BEM-AD3, BEM-AD4 |
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Micro-gebeuren Mei 1980, BEM-6 16/32K EPROM card |
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B.E.M. SBC4D(2) 6809 based CPU card on the BEM bus |
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MAiS, a system for airtraffic control, developed around the BEM SBCD4 and a custom card.
As editors of the magazine Radio Bulletin we had many conversations with them and wrote articles about their products.
For the KIM-1 and SYM-1 they had many products, some based on the so called BEM bus (DIN 31 pin connector), some as addons to the 22/44 edge connector of the KIM-1.
I stilll own this 4K RAM card:
BEM SBC4 in MAIS box
An example of a 6809 CPU board in a custom industrial application. Bought front eh HCC Forth UG in 2004.
