TRS-80 Model 12 versus 16B

Geoffrey Reed geoffr at
Wed Apr 26 00:32:04 CDT 2017

On 4/25/17, 7:52 PM, "cctalk on behalf of Jim Brain via cctalk"
<cctalk-bounces at on behalf of cctalk at> wrote:

>On 4/25/2017 9:47 PM, Peter Cetinski wrote:
>> The 16B released around 1984 is essentially a factory upgraded Model 12
>>with the card cage and the 6Mhz MC68000 subsystem consisting of a CPU
>>card and 1 or more 16 bit memory cards.  The 16B for a time was the best
>>selling Unix workstation in the world.
>So, the 16B has the KB conn on the machine, but the KB?
>And, the 16B has the Z80 motherboard, witht eh 68K in the cage?
>> The 6000 released in 1985 was a slightly enhanced 16B with the biggest
>>difference being the upgrade to an 8Mhz MC68000.  This system allowed
>>you to run XENIX 3.x and address up to 1MB of RAM.
>I thought the 16B could also do 1MB of RAM?
>Can the 6000 still run the Z80 Oses (like TRSDOS II and such)?  (I
>assume so, since you noted that all units of this entire line used a Z80
>for IO)

Also it was possible to pull the 64k chips from the ram board and put 256k
chips in, it required new PALs on the ram board at least, and possibly a
wire run for the extra address line.  Nanook at eskimo north used to run
on 16¹s and 6000¹s and used to upgrade the ram boards.

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