Dallas 1216E Clock/Calendar

Hardware questions and modifications
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Vorticon
Posts: 278
Joined: Fri Nov 27, 2009 6:25 am

Dallas 1216E Clock/Calendar

Post by Vorticon »

Last thing on my PCjr hardware list was the Dallas 1226E Clock/Calendar chip which arrived today, and to my delight was a breeze to install and setup.
Now I think I have a decently appointed system with 640K, 2 parallel ports, parallel Zip drive, Xircom parallel ethernet adapter, clock/calendar chip, mouse, joystick and monitor. It's time for me to try some programming now :)

Walid
Brutman
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Re: Dallas 1216E Clock/Calendar

Post by Brutman »

Your system is nearly identical to mine now. Instead of the Zip drive I use a parallel-to-SCSI adapter and a SCSI hard drive. I don't bother with the mouse - I don't want to tie up the serial port, and I don't have an MS Booster on this machine so I don't have a bus mouse.

My machine has a V20 CPU, a Racore keyboard adapter (so I can use a keyboard from a 5150 PC), and a speech sidecar as well. If you need a little extra speed, go for the V20 .. they can be found relatively cheap and it gives you a 5 to 10% performance boost for free. It also has the non-protected mode 286 instructions that the 8088 doesn't have, so slightly more software runs on it.


Mike
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Re: Dallas 1216E Clock/Calendar

Post by Vorticon »

Man! You keep giving me more projects to do :) Is the V20 fully backward compatible with the 8088?

Walid
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NEC V20

Post by Brutman »

Well, almost fully compatible. The only program that I know that does not like the V20 is Lode Runner, and that can be patched. (I don't have the instructions to patch it, but it was supposed to be something obvious.) Everything else works well, and because you get the extra instructions from the 80286 (real mode instructions only) you can run a little bit more software.

The small speed bump is worth the effort. Carefully remove (and save) the 8088. Carefully install the V20. Mind which way the pins go - don't install it backwards. The only difficulty will be if the 8088 was soldered directly to the motherboard. On some PCjrs this happened.

Mike
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Re: Dallas 1216E Clock/Calendar

Post by Vorticon »

My 8088 chip is socketed, so that should not be a problem. I found and bought a V20 on ebay, and I'll let you know how it goes.

Walid
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Re: Dallas 1216E Clock/Calendar

Post by Vorticon »

OK. 8088 out, V20 in. No issues so far :) I'll test it with a few games and see if there is a noticeable speed difference.

Walid
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