PET 2001 corrections

From: Larry Anderson <>
Date: Thu Jul 9 20:51:01 1998

> From:
> Subject: Re[2]: PET 2001

> >> Or is it 9"? I can't check mine because they are both locked in my
> >> father's bedroom at this hour.
> >
> > 9". All the ones I've seen were 9".

9", 8" the Commodore ads said 9" display... But of course there is only about
8" showing... reminds me of that class-action monitor suit, (Our agency will
make $9 for the three monitors it bought a few years back, in 2000, I still
have the refund cards.)

> I agree with Pete, not that it makes much difference.

> >> Supposedly the 2001N and 2001B came with 12" screens, but I've never seen
> >> one.
> No. Never. 12 inch screen on 4032 (or possibly 4016) and above only.

the 12" models used the new video display chip (and newer motherboard
w/speaker) for which only 4.0 BASIC was coded, only the 4000 series.

> First PETS: 2001-4 and 2001-8 (also called 4k PET and 8k PET). Blue trim,
> blue-white phosphor, mangled and rebadged cassette (I can't remember whose)
> that you open by lifting the lid.

they were SANYO decks, no tape eject button, you had to lift the lid, I have
two (one in the PET and one external!)

> Then: 2001-4 and 2001-8 get Black trim and C2N cassette deck

Black C2N, custom case, no counter. Nice looking deck too, I called that
design the 'brick' datasettes, the later cream 'brick' added a counter but
they wern't as reliable as the black ones. The best are the (VIC/64 era)
low-profile 1530s. Nice units!
> Then: Green screen.
> Next was the ROM upgrade. Usual models were 2001-8N, 2001-16N, 2001-32N,
> 2001-8B, 2001-16B and 2001-32B. These had full-sized keyboards and external
> C2N decks. In the UK, 2001-8N with tiny keyboard and built in C2N was
> common. This was not a new motherboard in an old case - the case was a
> different shape (slightly less tall). Larry has suggested that these might
> be the 2001-8K, K standing for Calculator (-style keyboard) (sic).

I got the 2001-8K from my Spring 1980 Commdoore Product Catalog, listed were:

  PET 2001-8K Integeral cassette, upgrade (they list as 3.0) ROMs
  PET 2001 Professional Computer (these were the N series, 8N, 16N, and 32N)
                                 graphics full-sized keyboard.
  CBM 2001 Business Computer (non-graphics keyboard, Upgade ROMs, etc.)
                                 listed as 16B and 32B
  CBM 8000 Business Computer (Available June 1980) 80 columns, 4.0 ROMs
                                 listed as 8016 and 8032

> >> PET 2001NT Teacher's PET. Same as 2001N, just rebadged
> I've never heard of 2001NT.

> > Mine is just labeled "PET 2001-8K" I think, with no 'N' or 'B' anywhere,
> > but mine has a 9" screen and a full-size keyboard with graphics symbols.
> Strange. Full size keyboard with graphics symbols should be 2001-8N

Commodore was not a wasteful company (at least in the beginning,) maybe they
used an older label?? I would not put it past em.

> > cassette-beside-the-keyboard. I've got one here. And the /B and /N series
> > were called 3000's not 2001 everywhere except the USA. The 12" versions
> Are you sure? I thought the 2001-8N and 2001-8B got renamed 3008 a bit
> later.

Never saw a 3000 in my neck of the woods, though I did see pictures (like in
the PET Personal Computer Guide, etc.) I think they were more abundant in
Canada and the UK.
> > didn't appear in the UK until later. According to my (USA) manual, the
> > 2001/B (aka 3000 here) was a 9" screen too. IIRC, the 4000 was the first
> > with a 12" screen,

[bzzz] Read above, the 8000 was the first 12" model.

> > The 12" screen version was
> > eventually called the 8000 series here, and had different firmware (and
> > up to 96K RAM I think, bank-switched).

The difference between a 4000 and an 8000 is an extra k of screen RAM and the
video startup code in one of the ROM chips.
The 64k expansion board came later and was fully integrated lastly in the 8296
(mainly european release)

> Um. The first with the 12 inch screen was the 8032. Different firmware
> and re-done video circuitry. Later some of that was put into 4032,
> making the "fat 40" Bank switched RAM made an 8096...
> > One of the differences between the business and home versions (apart from
> > graphics symbols on the keytops) was whether the machine powered up in
> > upper- or lower-case.
> Was it? That's weird!

Yep, darned annoying if you like the graphics symbols. The 4000/8000 series
also extended the line height by a pixel or two (thanks to the new VDC) which
left a gap between lines, can be gotten around by printing CHR$(142)
-uppercase, no gaps- and then poking 59468,14 -set back to lower case-. It
was a routine in the screen printing code doing it.

I think three or four graphics symbols were readily unavailable, (you would
have had to print them out with CHR$()s and then build your program lines
around them) two of which I really liked to use, that PET (at school) did't
get used much by me... (=P)

> Take a couple of steps back and get a wider view:
> PET had two internal character codes.
[clip alot of tech stuff]
> And that was the second problem. Later PETS swapped lower and upper
> case letters. So now ASCII codes 65 and up, which still mapped onto
> screen codes 1 and up, gave LOWER case letters, but you pressed SHIFT
> for upper case. However the OS and BASIC (one and the same, really)
> treated unshifted as letters, and shifted as meaningless graphics
> characters, whichever mode you were in.
> Confused? It is, isn't it!

One of the Original to Upgrade ROM fixes...
You knew the programmer had an old ROM PET when the case in their text was inverted.

> >> ROMs (which I think came out in 1979?) fix both of those things.
> About then. The monitor - hex only - replaced diagnostic routines in
> the original ROMs. A listing was actually given in the original PET
> manual, but I couldn't get it to work whenever I typed it in...

I have it on a Commodore tape and the diagnostic tape too!
> >> I don't have a machine with BASIC 4.0, so I don't know how that starts
> It says "COMMODORE BASIC 4.0" but I can't remember whether between *** or
> ###.
*** COMMODORE BASIC *** Original ROM
*** COMMODORE BASIC 4.0 *** 4.0 ROMs

> >> Upgrade ROM machines also have a Microsoft easter egg in them
> >> whcih is missing from the original ROMs.)
> Indeed. Type WAIT 6502,100

and you get a screen full of MICROSOFT!

> > There was a very-short-lived BASIC-2, and BASIC-3 (more-or-less the upgrade
> > ROM set) was around for a while before 4. 4 has extra commands for the
> > disk, instead of having to use the generic IEEE channel commands, but
> > otherwise it's almost the same as 3.

Short lived?? - it seemed to be around for a few years to me...

> I have heard all sorts of numbering schemes for BASIC versions. The
> only thing they agree on is 4. AFAIK, the BASIC in 3008 and friends was
> identical to the upgrade ROMs that went in original PETs.

I go by Original, Upgrade, small screen 4.0, and large screen 4.0, and 80
column 4.0.

There were enough differences in the small and large screen 4.0 ROMs to keep
some 4.0 games from working on large screen PETs.
> > Only the original ROMs start up with ***; all of the later ones used ###.
> That clears up my mystery above. Thank you.

[bzzzz] *** were used in 4.0 too, but at least they did add 4.0 to the message.
> >> It might also be important to mention that the PET has a timer that
> >> operates in real time. And it has the same character set(s) as the VIC-20

except for the british pound symbol which replaced the PET's back-slash (\)

> >> and C64

the 64 set was 'pudgyier' to reduce video artifacting on TVs

 but you can't switch between the upper/lower-case text character
> >> set and the upper-case/graphics set without issuing a POKE command. (Was
> >> it 49512,12 and 49512,14? My memory is rusty.)
> Hope this clears up some misconceptions.

and that is why I made the PET FAQ! ;)
Larry Anderson - Sysop of Silicon Realms BBS (300-2400bd) (209) 754-1363
Visit my Commodore 8-Bit web page at:
Received on Thu Jul 09 1998 - 20:51:01 BST

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