[HN Gopher] The "35-cent" Commodore 64 softmodem
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The "35-cent" Commodore 64 softmodem
Author : todsacerdoti
Score : 106 points
Date : 2025-01-19 05:42 UTC (17 hours ago)
(HTM) web link (oldvcr.blogspot.com)
(TXT) w3m dump (oldvcr.blogspot.com)
| johnklos wrote:
| This is brilliant and elegant. It's quite satisfying to have ways
| to have older computers communicate with the rest of the world.
| Thanks, Cameron, for preserving and extending this work from and
| history of John Iannetta.
| classichasclass wrote:
| Thanks, John! It was one of my favourite posts he made. It
| deserved a second life, and usefully, too.
| rzzzt wrote:
| Wow, the "POKE i,." notation does work. Are there any advantages
| to doing so instead of typing zero for the value?
| weinzierl wrote:
| For a moment I saw
|
| POKE 1,.
|
| and thought _" Oh, Noooo"_;-)
| rbanffy wrote:
| This is why Edsger Dijkstra hated BASIC so much...
| weinzierl wrote:
| Maybe, but it is not known that he did for that particular
| reason. The sales assistants in department stores on the
| other hand... different story.
|
| In the 80s stores often had home computers for display and
| for customers to try them out. Much like they have tablets
| and phones on display now. Kids being kids used to play
| pranks with these machines and one way to hang a Commodore
| 64 was POKE 1,0 (or POKE 1,.). The store employees hated it
| because they had to come and reset the machines all the
| time.
|
| For me POKE 1,0 will always be burned into my mind as a
| dangerous frightening command, hence the _" Oh, nooo "_. I
| do not have any information if Edsger Dijstra held similar
| feelings and whether they contributed to his hate for
| BASIC.
| rbanffy wrote:
| Sorry. I was joking. Dijkstra's criticism wasn't as much
| for the syntax.
|
| I would, however, prefer "POKE X" as a shorthand for
| "POKE X, 0", but this might as well be a bug of the
| parser rather than an intended feature. Code had to be
| very compact back then.
| glimshe wrote:
| Dijkstra did much for computing, but an entire generation
| of developers inspired by and initially taught by BASIC did
| a LOT more.
| rbanffy wrote:
| Me included, BTW. BASIC was the first language I learned
| (second if we count programming a TI-55 calculator as
| first).
| the-rc wrote:
| The BASIC interpreter parses numerical values from text each
| time a token gets executed. It converts that into a float and,
| in the case of POKE, then into an integer. Using the dot
| without the implicit leading zero, there's no need to convert a
| "0" (48 in decimal) into a zero and, possibly, a multiplication
| by 10 of previously parsed digits, in this case the starting
| zero value.
| rbanffy wrote:
| If it's one-way, it's just a "mo". The "dem" part will only be on
| the other side.
| ajb wrote:
| One thing to bear in mind, if anyone feels like trying out this
| old stuff, is that modems relied on the latency being absolutely
| fixed; as was guaranteed in the POTS network - and of course an
| analogue connection. Modern VoIP calling does not guarantee this
| at all, and even if you have a landline it will almost certainly
| have been converted to run on VoIP by now. There were
| compatibility fixes (such as V.150.1) but given the limited usage
| it would not be surprising if they have bitrotted at this point.
| OhMeadhbh wrote:
| Heck. I've been wondering what to do with the WorkSlate in my
| closet.
| classichasclass wrote:
| Hopefully the cassette drive still works. That would be a rare
| bird - the three I have, even one minimally used one with the
| film still on the LCD, the tape drive is already dead. It seems
| to be a mechanical problem, not (just?) caps.
| OhMeadhbh wrote:
| Alas. The cassette drive is borked. Every couple months I
| think about trying to fix it, but then some other shiny
| object gets my attention. I've not even tried to figure out
| what's wrong with it.
| leptons wrote:
| >An important warning before we continue: from the telephone
| company side the line pair carries voltage used to power the
| phone and ringer, so never plug this cable into a wall jack --
| doing so could potentially send up to 48 volts to the computer,
| with likely undesirable and even fiery results. A cable like this
| should only ever be directly connected to another modem.
|
| I tried this exact thing way back in 1985 or 1986. I wanted to
| use the C64's sound chip as a modem. I also had a PLL chip to
| decode received tones.
|
| I was a teenager at the time and I didn't realize the voltage on
| the phone line was so high, so yeah, I fried my C64 pretty
| quickly. That was the end of that experiment.
|
| I did eventually make a 300 baud modem using speaker coupling to
| a telephone handset, but I had to save up to buy a new C64 first.
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