Beogram 8000

The last two of the four initial projects, Beomaster and Beogram 8000, now also started to become critical with program development and space in the TMS9940. I took over the program for Beogram 8000 written by John Kraack and got it running with TMS9940 emulation while he continued with electronics development. Since TI still could not supply the TMS9940, it was decided to use a Rockwell/MOS Technology 6500/1 single-chip microcomputer as a replacement. This is an 8-bit integrated circuit with 2K ROM and 64 bytes of RAM with the same instruction set as the 6502 used in early Apple and Commodore computers, among others. As far as I recall, this was not available in an EPROM version, but could be obtained in a special plug-in module, where together with a compatible processor and some I/O circuits a 2716 (2K byte) EPROM or similar could be mounted.

My next task was to rewrite the Beogram 8000 program for the 6500/1 processor. At the same time the Beomaster 8000 program was converted to two MOS Technology 6500/1s by Brian (Knott?), a consultant from an English company (Thurston?) who had been working on some software for B&O’s instrument department. Tom Jelsing continued with electronics development for the Beomaster. The two products were launched (but not delivered) at the same time, and now the link connection between the three devices in the Beolab 8000 system could finally be used by users. Two Rockwell development systems were purchased so that both projects could be developed in parallel. These used 5.25″ floppy disks and had noisy fans which Tom Jelsing cured by reducing them to half speed.

One of the new and unusual features of the Beogram 8000 was the direct drive of the platter with a linear motor. An aluminium plate under the turntable shaped like a saucer with vertical edges is turned by electromagnets controlled by the microprocessor. In the same way as an old-fashioned electricity meter. A tachometer disc with very precise markings is detected by an optical sensor, so the exact rotation speed is measured many times for each revolution. The parallel tonearm was known from earlier Beogram models, but here it was controlled by the microprocessor.

The rotational speed of the turntable can be changed by the user in small steps either faster or slower than the standard 45 and 33.33 speeds. The size of the gramophone record is measured by the arm which is parallel to the tone arm, by light reflected from the turntable. A small LED display built into the keypad shows speed and other status information. There is no secondary control panel, but the aluminum cover can be opened to provide access to the tonearm when parked, as well as an insert for 45rpm records with large center holes.

The Beogram 8000 can be connected to the same link system as the Beomaster 8000 and Beocord 8000, so when a record is played, the Beogram 8000 can cause the Beomaster to turn on and switch to gramophone and possibly stop Beocord playback. From the remote control the user can also start the gramophone playback.

Since all 4 projects were developed in parallel, four TI development systems were initially purchased, electronics were designed for the TMS9940 40-pin single chip processor, and many hours spent on the four programs. This investment in resources and equipment probably delayed the switch away from the TMS9940 in the last two or three of the projects for as long as possible. It was expected that a company of Texas Instruments’ size and resources could produce and supply the processor, since they already had a compatible processor without built-in RAM and ROM.

A Danish retail price list from 1 September 1980 shows no price for the Beomaster 8000, but indicates delivery in early 1981. The Beocord 8000 and Beogram 8000 each cost DKK 4,560, with delivery of the Beogram 8000 expected at the end of September 1980. In February 1982, the Beomaster 8000 cost DKK 11,595. To this a pair of passive loudspeakers had to be added. The Beocenter 7000 cost 8,415 DKK.

Next chapter: Beomaster 6000