ClausB Posted August 16, 2015 Share Posted August 16, 2015 The cassette audio interface was on a daughterboard which I don't have. It ran at either 300 or 1200 baud, through the UART on the main board. That UART can be clocked at up to 480 kHz for up to 30 kbaud, though the cassette driver in the Monitor ROM might not keep up at that rate. I plan to tap one of the video counter bits for the UART clock to get between 6 and 24 kbaud, and program the Arduino to match that rate. 1 Quote Link to comment Share on other sites More sharing options...
tep392 Posted August 16, 2015 Share Posted August 16, 2015 That was a lot of chips to replace. Do you remember what they cost? Quote Link to comment Share on other sites More sharing options...
ClausB Posted August 16, 2015 Share Posted August 16, 2015 I kept a ledger on the envelope containing the photocopied schematics. $247 including keyboard and transformer in 1981. A lot but still much less than the price of a Sorcerer. 1 Quote Link to comment Share on other sites More sharing options...
ClausB Posted August 19, 2015 Share Posted August 19, 2015 D'oh! The Arduino can simply generate the UART clock itself. Quote Link to comment Share on other sites More sharing options...
Tempest Posted September 4, 2015 Share Posted September 4, 2015 I have a chance to possibly get an Exidy Sorcerer II, but it has an issue. Before I even consider it, I want to know if this is something that is easily fixable. He says that the letters have a 'distortion' to them: The letters on the screen has a visible black retrace line going through it. Running up the down. I did check the power supply ripple which is the AC noise on the regulated DC voltage outputs and it was ok. So I don't think the power supply capacitors are the issue Any ideas? EDIT: He sent me a video. Looks like it could be a loose chip or possibly something with the display circuit. Exidy.zip Quote Link to comment Share on other sites More sharing options...
Tempest Posted September 5, 2015 Share Posted September 5, 2015 No ideas? Quote Link to comment Share on other sites More sharing options...
LoTonah Posted September 5, 2015 Share Posted September 5, 2015 It could very well be the monitor, I've had monitors ripple like that before. Did he try hooking up something different? Quote Link to comment Share on other sites More sharing options...
Tempest Posted September 5, 2015 Share Posted September 5, 2015 It could very well be the monitor, I've had monitors ripple like that before. Did he try hooking up something different? Yeah he tried two different monitors and several cables. That was one of my first ideas too. Of course that doesn't mean that it might not like either of his monitors. Quote Link to comment Share on other sites More sharing options...
Tempest Posted September 6, 2015 Share Posted September 6, 2015 I think I'm going to go for it. I'm hoping it's just a loose connection or bad cap. Quote Link to comment Share on other sites More sharing options...
Tempest Posted September 6, 2015 Share Posted September 6, 2015 The monitor reports that the top of the stack is FFFF (64K) when in reality it should be BFFF (48K). Anyone know why this might be? Quote Link to comment Share on other sites More sharing options...
ClausB Posted September 7, 2015 Share Posted September 7, 2015 (edited) Nice find! The video jitter should be fixable - might be marginal timing somewhere in the display circuit. Full schematics are in the HW Ref on this site: http://www.trailingedge.com/exidy/ The FFFF top of RAM means that the Monitor detected a RAM failure at address 0000. See the listing on p. 25 of the SW Ref from that site. So some part of the DRAM has failed but the Monitor is working out of the character SRAM at the top of memory. Maybe you can use this failure to negotiate a lower price. Edit: On second thought, both these problems could stem from bad +5, +12, or -5 V power. Like you said, maybe a bad cap. Edited September 7, 2015 by ClausB Quote Link to comment Share on other sites More sharing options...
ClausB Posted October 16, 2015 Share Posted October 16, 2015 Updates: Tempest and I got his II working. It had a shorted cap on the 12V line. Also I got my I working. Just had to reseat the chips. I also fixed the horizontal jitter. Surprisingly it was a design flaw in the circuit. The low bit of the horizontal counter was reloaded from the flipflop that blanks the video during screen RAM access. So when the CPU wrote to the screen the HSYNC period would change a little, causing jitter. I rewired the bit to the flipflop's input and it's solid now. The flaw even made it into the II, so we will fix tempest's too. I got the Arduino tape simulator working too. It even runs at 20833 baud! That's under 30 seconds for a 48K tape image. Yay. 3 Quote Link to comment Share on other sites More sharing options...
Opry99er Posted October 16, 2015 Share Posted October 16, 2015 That is awesome news!!! Quote Link to comment Share on other sites More sharing options...
Opry99er Posted October 17, 2015 Share Posted October 17, 2015 Any chance we could get some pictures/screenshots? This is a fascinating computer. Did it have built in BASIC? Quote Link to comment Share on other sites More sharing options...
Tempest Posted October 17, 2015 Share Posted October 17, 2015 I plan on posting some clips of it soon. No built in Basic, only a Monitor program. Basic was provided on a cartridge which was housed in an 8-Track case. 1 Quote Link to comment Share on other sites More sharing options...
Opry99er Posted October 17, 2015 Share Posted October 17, 2015 Quote Link to comment Share on other sites More sharing options...
Tempest Posted October 19, 2015 Share Posted October 19, 2015 I haven't had a chance to do a video of my Sorcerer, but Tezza has a great video of his Sorcerer running some programs. Check it out: 1 Quote Link to comment Share on other sites More sharing options...
Opry99er Posted October 19, 2015 Share Posted October 19, 2015 Man,that makes me want one!!! A very capable computer, it seems. Quote Link to comment Share on other sites More sharing options...
Tempest Posted October 19, 2015 Share Posted October 19, 2015 It's a really neat computer, but it's also kind of limited since it didn't last too long. In a way it reminds me of the TRS-80 but with Hi-Res graphics. Quote Link to comment Share on other sites More sharing options...
JamesD Posted October 19, 2015 Share Posted October 19, 2015 It's a really neat computer, but it's also kind of limited since it didn't last too long. In a way it reminds me of the TRS-80 but with Hi-Res graphics. If I remember right, that was pretty much the goal of the designer. He thought the TRS-80 was a good computer but needed higher resolution graphics. I can't say I disagree. Quote Link to comment Share on other sites More sharing options...
Tempest Posted October 19, 2015 Share Posted October 19, 2015 I just wish it had gotten the support the TRS-80 did. Towards the end of the TRS-80's life there were some amazing looking games being released even with its simple graphics. The Sorcerer got some nice arcade clones, but only a handful. I'd love to see what people could have done with the Sorcerer and its hi-res graphics. Quote Link to comment Share on other sites More sharing options...
ClausB Posted October 21, 2015 Share Posted October 21, 2015 Here's the Arduino Mega tape sim: and BASIC loaded: The RAM48 program relocates the MWA to the top of 48K instead of 56K so that BASIC will load properly. Quote Link to comment Share on other sites More sharing options...
Opry99er Posted October 21, 2015 Share Posted October 21, 2015 Too cool... Quote Link to comment Share on other sites More sharing options...
ClausB Posted January 8, 2017 Share Posted January 8, 2017 tempest and I built a BASIC ROM Pac for his Sorcerer II. Its 32K EPROM holds 4 versions of Exidy BASIC but we haven't added the selection switches yet. Aside from wiring the rat's nest on the back, the hardest part was figuring out what plastic to cut out of the 8-track case. Quote Link to comment Share on other sites More sharing options...
Tempest Posted January 10, 2017 Share Posted January 10, 2017 Now that I have a BASIC cartridge I can run a few more programs such as Super Star Trek (every classic computer needs to run Star Trek!). I also managed to find the listing for Wizards Castle which was originally done on the Sorcerer (in the computer shop that ClausB worked at no less). I'll let everyone know when I get it up and running. 2 Quote Link to comment Share on other sites More sharing options...
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