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

From: Don Maslin <donm_at_cts.com>
Date: Mon Feb 15 14:03:02 1999

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 :{

                                                 - 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 - 14:03:02 GMT