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Most versatile vintage add-on?


Keatah

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What do you think was/is the most versatile add-on or expansion peripheral for your fav vintage rig?

 

I will vote The Apple Cat II "modem".

 

Though it was much more than just a modem. It was a sound synthesizer, "box" tone generator, clock, RS-232, BSR X10 controller, 300/1200 half & full duplex modem, DTMF Touch-Tone decoder & generator, answering machine, voice digitizer & speech recognition tool, voice distorter, among other things. Tons of phreaking and dialing stuff was also written for this card.

 

It was nice because it was rather open-ended and Novation published the schematics and ROM firmware and registers - thus making experimentation and programming comparatively easy.

 

I was always fascinated that the CAT could function as a clock card. It was middle-ground. You see. Back in the day there were three different types of "clock cards" for the Apple II.

 

1- 100% software based

2- A ghostly middle-ground solution in the form of the Apple Cat modem.

3- A real 100% hardware based solution with its own battery and oscillator and clock chip, like an add-in board.

 

Having your computer display the time and date and make a log when a user signed-in was a big stink back then. It was useful to the sysop for tracking down and booting the leechers while at the same time (no pun intended) showing sophistication.

 

My first solution was to make a small routine and display the time all through software running on the main 6502. This worked pretty well, but it slowed down the BBS slightly. Time was hopefully, mostly, divided between the clock routine and the running BBS. This all went to hell when there was disk access. When reading/writing, the clock would essentially stop and lose time.

 

A work-around was to keep track read/write activity and factor in the size of the data set and re-add that back to the stopped clock. We even compensated for the 1/2 second motor startup. But only took an average of Track-to-Track seek time. We could have done it exactly, but we never got that deep into watching RWTS and what it was doing. That it all worked was nothing short of amazing! A clock with no added hardware! Innovation 2BShure!

 

The next step up was the Cat-Clock. This relied on timers in the modem and thus maintained time during disk access and other interrupting activities. This was incredible, it was a re-purposing of hardware the likes of which we had never seen before. Was there really a hidden clock in the modem? No of course not. But it worked amazingly well.

 

#3 was ultimately the best solution. Naturally. There were comprehensive full-featured cards that supported all the contemporary BBS software, DOS, and PRODOS, and offered good Applesoft BASIC compatibility - for a cost around $100-$200 bucks. I eventually settled on the Applied Engineering TimeMaster II H.O. But before doing that I used the Cat-Clock for a long time. All summer long and partly into winter IIRC.

 

 

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Another thing partly worth mentioning is that most Apple II interface cards typically had a socket for 2K ROM on them. Printer cards, serial cards, modem cards, and of course dedicated ROM cards like the official Apple ROMCARD or Mountain Hardware's ROM+ board. And especially the SpeechLab recognition card from Heuristics.

 

In fact there are two separate circuits on some of those boards. Two electrically independent circuits. One for the interface "function-U-got-the-card-for" part. And the other to connect the ROM to the bus. Essentially the 2nd circuit - interfacing the ROM to the bus - enabled the ROM to run a stored dedicated-function program.

 

In the case of the Grappler it was for like screen sizing and capture. Modems had simple terminals. And A tiny 2K program was called into play and executed like it was loaded from disk. Not a big deal in the scheme of things but mind-blowing to a kid just learning and discovering this stuff.

 

These cards, like the Grappler+ printer interface card can play host to other totally unrelated ROMS, like utility ROMS, a fast-DOS loader, memory inspector, additional BASIC commands, Programmer's Aids, or whatever. It's something I didn't do too much of back in the day because I was so busy with playing games and farting around other stuff.

 

Edited by Keatah
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2 minutes ago, wierd_w said:

In the PC world, the boot rom socket in many old ISA network interface cards could do the same.  It is exploited in the modern era to get the XT IDE bios on ancient systems.

At the time of its release though, it was revolutionary.

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