Tek 4050 series (was:Re: Questions on the days finds)

From: Joe <rigdonj_at_intellistar.net>
Date: Mon Feb 15 16:15:24 1999

At 12:03 PM 2/15/99 -0800, you wrote:
>On Mon, 15 Feb 1999 Philip.Belben_at_PowerTech.co.uk wrote:
>
>>
>>
>> >>> Yes but what's interesting is that the bit-slice 4052 is software
>> >>> compatible with the 6800 powered 4051!!! The 4052 is a 16 bit machine.
>> I'm
>> >>> guessing that Tektronix used the bit slice CPU so that they could
>> retain
>> >>> the same software but gain the power of the 16 bit system.
>> >>
>> >>>From what I recall (looking at Philip's 4052 service docs), the
>> >>instruction set is not identical. There's at least one 6800 instruction
>> >>missing on the 4052.
>> >
>> > That's odd unless they (Tektronix) never used that instruction since
>> they
>> > claim the the 4052 and 4054 will run all the 4051 software.
>>
>> Don't forget that at the user level, the 4050 series were BASIC machines.
>> Any BASIC program that would run on the 4051 would run on the 4052. Some
>> of the BASIC programs that needed ROM cartridges on the 4051 would run on
>> an unexpanded 4052.
>
>And also that the command for direct access to machine code level was NOT
>proffered to the customers. Some of the field guys would provide it to
>customers that they liked, but it was not policy to do so. Certainly,
>also, some of the more knowledgeable users hacked it.
>
>Unfortunately, I have long since forgotten it :{

   Arrggg! I can't believe you forgot that! That's like saying you found
the holy grail, then lost it!

    Joe
>
> - don
>
>> Talking of BASIC, I think most of the cartridge ROMs were BASIC extensions.
>>
>> > Does the 4052 service manual give that level of detail? The one for
>> the
>> > 4051 gives NO information on the CPU instruction set other than what was
>> in
>>
>> Not much detail, but it explains the addressing modes and lists the
>> instruction set (although it doesn't tell you what the instructions do).
>> It explains the CPU architecture, including the microcode format...
>>
>> > the Motorola 6800 brochure that's included in the manual. Does the 4052
>> > manual give the entry points of the software routines in the system ROM?
>>
>> Alas, no. Not a thing. I wish it did!
>>
>> > The 4052 and 4054s also have a larger address range and more memory,
>> > that may also be why their ROMs won't work in the 4051.
>>
>> In part. As I said earlier, I think "software compatibility" meant BASIC
>> software.
>>
>> >>At the hardware level, the 4052 is 16 bit. But the microcode implements
>> >>an 8 bit processor - the 16 bit operations are used for calculating
>> >>addresses only.
>> >
>> > I wondered if they were using all 16 bits for data since they could use
>> > the 8 bit 4051 ROMs.
>>
>> The memory management circuitry is a tour de force. Not only does it
>> handle 16 bit fetches on odd and even bytes, it will decide whether you are
>> addressing 8 bit wide or 16 bit wide memory and act accordingly. Really
>> lovely machine.
>>
>> Yes, the 4052 ROM cartridges are 8 bits wide.
>>
>> Philip.
>>
>>
>
>
Received on Mon Feb 15 1999 - 16:15:24 GMT