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Questions tagged [commodore-pet]

Questions regarding the Commodore PET range of microcomputers.

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Memory gap in Commodore PET

Most largish programs written for the Commodore PET have a bunch of rem statements somewhere around the 8K or 16K area. The normal comment is something to do with a hole in memory. I remember PET ...
cup's user avatar
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8 votes
1 answer
2k views

How were printouts done on Commodore PETs

In the old PC mags, there were often printouts of code from Commodore PETs. How were these done? Even though the PET had a GPIB interface, it didn't have a print command. The method that we used in ...
cup's user avatar
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2 votes
0 answers
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Eventual garbage screen on Commodore PET 2001N

I have a Commodore PET 2001N 32K that boots and runs fine but eventually (sometimes minutes, sometimes hours) it goes to a garbage screen, and it will stay that way if I immediately cycle the power. ...
RedFilter's user avatar
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3 votes
2 answers
371 views

PET game database has disappeared, new location? [closed]

Some time ago I was pointed to a great site with PET games.... which has since been hijacked. Does anyone know if this moved to a new location? Google fails to turn up anything related, although ...
Maury Markowitz's user avatar
3 votes
1 answer
206 views

What is the advantage of using CB2 over CA2 on the PET user port?

According to schematic 320130-1 (from zimmers.net) the user port on the PET brings out from the 6522 PIA all data lines from port A (PA0-PA7), the port A input-only handshaking line (CA1), and the ...
cjs's user avatar
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24 votes
1 answer
2k views

Why was PETSCII based on an obsolete version of ASCII?

PETSCII (sometimes PETASCII) is the character set developed by Commodore for use in its microcomputers. The first of these, the PET, started to be developed in early 1976. Why, then, did Commodore ...
Psychonaut's user avatar
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8 votes
3 answers
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Why didn't the original Commodore PET computer use a standard typewriter style keyboard?

Being a huge fan of Commodore, I've often wondered why Commodore would use such a horrible keyboard layout for their premier computer utilizing an alpha-numeric keyboard. My only guesses would be ...
Hitek's user avatar
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10 votes
0 answers
395 views

Was the RPL language for the Commodore PET ever used other than by its author?

Note that this question is about the programming language RPL for the Commodore PET, not the HP language with the same name. RPL was developed by Tim Stryker and sold through his company Samurai ...
WimC's user avatar
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15 votes
2 answers
2k views

How should I repaint my Commodore PET?

I have an original Commodore PET from 1977, that I have recently electrically restored, but there are some rust spots on the case. It seems that I should at least do something to inhibit further ...
Edward's user avatar
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20 votes
1 answer
3k views

What's the deal with Commodore's RESTORE key?

Most early microcomputers provided either a dedicated key (e.g. Apple ][), keyboard combination (e.g. PC clones), or dedicated hardware button (countless examples) to "Reset" the computer. ...
Brian H's user avatar
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8 votes
1 answer
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Did the keyboard "scancodes" available to Commodore PET software differ between models?

As mentioned on my Were there any standard tricks to fix PET upper/lower case differences? question, I'm trying to figure out what to expect when running software generically labelled as "PET&...
natevw's user avatar
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5 votes
1 answer
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Were there any standard tricks to fix PET upper/lower case differences?

I have a Commodore PET 4016 like the one described here but did not grow up with any Commodore computers and I am still learning where it fits in their line-up and even how to use it. After buying a ...
natevw's user avatar
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10 votes
1 answer
906 views

PET as a terminal

While reading about the SuperPET I just recalled another PET modification. My uni had an 11/780 that I learned FORTRAN on. It used modified PETs as input terminals. This took the form of a modified ...
Maury Markowitz's user avatar
4 votes
1 answer
340 views

From what errors could Commodore's tape loader recover

The Commodore PET/VIC-20/C64 tape routines write out the leader for each file twice, and then write the data twice. While it would seem that this should allow data to be loaded more reliably, ...
supercat's user avatar
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5 votes
2 answers
769 views

CBM PET 2001 garbled screen

I picked up this PET and trying to restore it. Screen is garbeled on boot and stays like that displaying random chars, some of them flashing. Tried to resocket the chips, but it didn't help. I don't ...
Bartek Malysz's user avatar
17 votes
3 answers
3k views

C64/PETSCII block graphic symbol: was there ever a logical reason for their "ASCII" codes?

You know those block graphic symbols that allows you to draw lines, corners, intersections, fine bar charts, etc. they are useful and one can do a lot of stuff, but their code arrangements always ...
Gunther Schadow's user avatar
8 votes
2 answers
845 views

Why did the Commodore PET 2001 take so long to ship?

In 1976 Commodore as a company had been running for more than twenty years and had extensive experience with designining and selling consumer electronics products: they were one of the top-selling ...
cjs's user avatar
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7 votes
2 answers
787 views

What's the timeline of Commodore diskette drives?

Commodore produced a number of different floppy diskette drive units, both 8" and 5.25", over the course of its history. Can someone provide a chronological list of the drives, their release dates, ...
cjs's user avatar
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12 votes
2 answers
1k views

Did all integrated Commodore PET monitors always use 60 Hz refresh?

All models of the Commodore PET line had built-in monitors, and at least the U.S. models had 60 Hz refresh. For the European models there was no need for compatibility with European television ...
cjs's user avatar
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6 votes
0 answers
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PET LOAD command and the < key

I remember reading (probably in some issue of the newsletter of the PET Benelux Exchange (PBE)) about a strange effect during tape loading of a PET program. Back in the day, I tried it and it worked. ...
Rhialto supports Monica's user avatar
5 votes
1 answer
752 views

What were Commodore's keyboard layouts before the VIC-20?

Starting in 1980 the VIC-20 keyboard seems to have become sort of a standard for Commmodore, being re-used on the MAX Machine (in membrane form), C64, C16 and (with additional keys added) the 128. ...
cjs's user avatar
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9 votes
3 answers
2k views

What's the first use of the term, "1977 Trinity"?

The term "1977 trinity" has been used, here on Retrocomputing SE and elsewhere, to refer to a set of three computers that started shipping in mid- to late-1977: the Apple II, the TRS-80 ...
cjs's user avatar
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3 votes
1 answer
489 views

Transatlantic gray market Commodore PETs and 220V/50Hz vs. 115/60Hz

In the late seventies, Commodore sold the PET in Europe at a considerably higher price than in America; they could get away with this because there was less competition there. Some of the American ...
rwallace's user avatar
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9 votes
3 answers
620 views

PET game, enemies attempt to break through several concentric sets of walls

I'm looking for another PET game, which I cannot find on various sites. It was one of the earlier ones - it was available when I first got access to the PETs circa 1981/82. The user starts in the ...
Maury Markowitz's user avatar
16 votes
1 answer
1k views

How did the Commodore PET 80 column display work?

Some variants of the Commodore PET (e.g. the 8000 and 9000 series, as well as some other versions with an aftermarket add-on) produce an 80x25 character display. Their character set is fixed in ROM ...
Jules's user avatar
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9 votes
4 answers
1k views

Columns of text in early microcomputers

As discussed in some previous questions here, 80-column text was established by IBM as the standard for business computing as early as the sixties, but monitors capable of displaying that resolution ...
rwallace's user avatar
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30 votes
5 answers
10k views

Why were early personal computer monitors not green?

Green was traditionally the most common color for computer monitors; it combines strain-free readability with low cost. Given this, it's surprising that the first versions of the Commodore PET and ...
rwallace's user avatar
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8 votes
2 answers
1k views

Is it possible to bank out Kernal in Commodore PET, VIC-20 or 264 series computers?

You can bank out Kernal ROM in C64 using $01 register. This was preferred by game/demo coders who wants to employ self tuned routines and wants to expose ram 'underneath'. You can do lda #$35 : sta $...
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13 votes
3 answers
952 views

Origin of copy-protection dongles

The first time I ever heard of a dongle was when it was used on a text processor called Wordcraft on the Commodore 8032. It was around 1980. We had three machines and had to share the dongle amongst ...
cup's user avatar
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10 votes
4 answers
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Who wrote the MS BASIC on the PET/C64/etc?

I'm wondering if anyone has a document that describes the history of the BASIC interpreters used in the various Commodore 8-bit machines? Ultimately I'm trying to track down how it is that the A% ...
Maury Markowitz's user avatar
16 votes
2 answers
2k views

PET space arcade game with surprisingly good graphics

We had PET computers in my high school, 4032's IIRC, and a few classic games to go with them - the excellent Space Invaders port, Star Trek of course, and a few others. These all used PETASCII for ...
Maury Markowitz's user avatar
21 votes
4 answers
2k views

Obscure uses of the Commodore 8050/1541 disk drive

When I was working for a foundry consultancy, we did the following Download routines to add delays when writing certain tracks. This was a security feature. When the program started, it would try ...
cup's user avatar
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10 votes
3 answers
1k views

Transferring files between Commodore PET and IBM PC

Suppose you have two early eighties computers, a Commodore PET with 8050 disk drive and an IBM PC with its 5.25" disk drive. Is there a way to transfer files between them? Not machine code programs, ...
rwallace's user avatar
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18 votes
6 answers
1k views

Is there software that will run across multiple Commodore 8-bit machines without modification?

I noticed in some of the answers in this question that the Commodore 8-bit line apparently used a jump table at $03xx for entry into the kernel ("kernal" for the pedantic) routines. Figuring that the ...
bjb's user avatar
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16 votes
4 answers
2k views

Computers with integrated monitor (all-in-one form factor)

The Commodore PET had an all-in-one form factor where the monitor was fused into the rest of the computer, making a single unit, not dissimilar to some early terminals like the VT100. This is ...
rwallace's user avatar
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9 votes
3 answers
553 views

Origin of dealer networks

Roughly speaking, the two main ways to sell computers are, and particularly were in the old days, Three digit price tag sold to individuals => mass market, department stores and suchlike. Four digit ...
rwallace's user avatar
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49 votes
6 answers
7k views

Can a PET 2001 be physically damaged from BASIC?

In the early 1980s my primary school was the proud owner of a Commodore PET 2001. There was a commonly held belief among the young geek fraternity that there existed a BASIC command—perhaps a ...
Flup's user avatar
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20 votes
2 answers
851 views

What was the end of line convention for text files on the 8-bit Commodores

A two part question: Did an agreed upon convention for end of line (EOL) within text files exist on the 8-bit Commodores? If there was a convention, what was it?
Shannon Severance's user avatar
16 votes
2 answers
1k views

What is this code on the zero page that was put there by the BASIC ROM?

(question copied from SO (from the days before RC.SE existed): http://stackoverflow.com/q/31877835/477476) Zero-page memory maps of the PET that I've found claim that the zero page address range$00C2....
Cactus's user avatar
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