Some on this list might be interested to read about my latest acquisition: http://www.classic-computers.org.nz/blog/2011-06-08-sorcerer-acquisition.htm I've also added the model to my collections site: http://www.classic-computers.org.nz/collection/exidy-sorcerer.htm The only thing to do now is to replace or repair the BASIC ROM-PAC Terry http://www.classic-computers.org.nz

Oh - I forgot... I may have a RAM pack - I will have a look on the weekend. If I have one - I will happily dump a ROM for you. Doug On Fri, Jun 10, 2011 at 11:05 PM, Doug Jackson <doug at doughq.com> wrote: -- Doug Jackson VK1ZDJ http://www.dougswordclock.com/ -< My clocks http://www.vk1zdj.net -< My Amature Radio Activities

Ahh - sorry about that - I meant ROM pack. It is great that you have the images - now you just have to wrestle with the eprom programmer :-) Doug On Mon, Jun 13, 2011 at 7:11 PM, terry stewart <terry at webweavers.co.nz>wrote: -- Doug Jackson VK1ZDJ http://www.dougswordclock.com/ -< My clocks http://www.vk1zdj.net -< My Amature Radio Activities

Woot! I don't have the S100 expansion unit for the scorcerer. I do however have a number of unpopulated S100 cards to allow me to make a complete S100 system one day - I just need to get a 4 - 8 slot backplane for less than the stupid amount that people on Ebay are charging..... Take care :-) Doug On Tue, Jun 14, 2011 at 4:17 AM, Tony Duell <ard at p850ug1.demon.co.uk> wrote: -- Doug Jackson VK1ZDJ http://www.dougswordclock.com/ -< My clocks http://www.vk1zdj.net -< My Amature Radio Activities

Or perhaps more useful, when switching ON! (sorry..typo) Terry (Tez) ----- Original Message ----- From: "Terry Stewart" <terry at webweavers.co.nz> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Sent: Wednesday, June 15, 2011 1:22 PM Subject: Re: New rest-home resident: An Exidy Sorcerer >> I must get mine set up again. From where I am sitting I can see the fornt >> side of the S100 expansion unit... > > Nice. I would love an expension unit for the Sorcerer but is was hard > enough to actually find the computer itself here in New Zealand. I think > it will have to remain one of those wistful thoughts. > > I've decided to have a crack at fixing this BASIC ROM-PAC over the next > few months. This is probably a good opportunity to actually LEARN about > burning EPROMS and I'm sure I'm going to need to do so if I want to keep > my 70's and 80's computers going for the next 20 years. > > It's going to be a big learning curve for me as my knowledge is still > fragmented in this area. Also it's likely to be a slow project as there > are lots of competing activities at the moment. However, hopefully you > guys can assist if I need to ask what (to you) might seem stupid > newbie-type questions. > > Of course I'm only ASSUMING it's the ROMS. There is not much else in the > case though apart from a few caps and a logic chip or two. Is there any > quick technique to determine if it IS the ROMS and if so if any particular > ROM is faulty? > > One way that comes to mine with the Sorcerer is to somehow prevent the > ROM-PAC from autostarting, then peer into the memory locations the ROM-PAC > occupies (with the inbuilt monitor) to see if any of the memory seems > messed up (with repeating patterns etc.). If NONE of the memory locations > appear accessible this would indicate it might be something OTHER than the > ROMS yes? (as it's unlikely all 4 ROMS would have developed a fault). Is > this a reasonable approach to start off? > > > Anyway...I'll report any progress. > > Terry > > >

Very clever!! If you have this level of diagnostic ability, then you will find burning eproms a cake walk! Doug ! On Wed, Jun 15, 2011 at 8:17 PM, Terry Stewart <terry at webweavers.co.nz>wrote: -- Doug Jackson VK1ZDJ http://www.dougswordclock.com/ -< My clocks http://www.vk1zdj.net -< My Amature Radio Activities

On 2011 Jun 15, at 3:17 AM, Terry Stewart wrote: Great work! Just a suggestion, one more thing you might check, as confirmation, is to place the suspect ROM chip in another location and look at the contents from there, to confirm that it is the ROM chip and not the ROM-selection circuitry or something particular to that chip position causing the problem (although it probably would show all-FFs if it was the selection circuitry).

On 2011 Jun 15, at 11:14 AM, Tony Duell wrote: Right, that's checked then. I think I saw the addressess with x000 in them and thought he was using the lowest chip location for the test.

Thanks for the encouragement RE: the Exidy Sorcerer BASIC ROM-PAC. This weekend I'll unpack the ROM burner, read the docs that come with it and take it from there. In the meantime here is another thing to ponder. I had problems loading in machine-language (not BASIC of course) software seem to load successfully expect for the shortest program. Ok, so I figured the tapes were just old and degraded. Googling around and trying things out I found I could make sound files (WAV) from cassette binary archives of Sorcerer software using the MESS emulator. Hooray! BUT...loading these into the Sorcerer via soundcard seemed tricky. No matter how much I fiddled with the volume and tone controls, an error always seemed to appear about 45 seconds to a minute into the run. Very fine adjustments made a slight difference, but the only program I could get to load in was actually a copy of the short file (Martian Invaders) that I'd successfully loaded via real tape. Off the top of my head I think it was just over a minute long (it could be longer). I looked at the WAV file with Audacity. They were nice square waves with a good amptitude. They certainly LOOKED ok. Hmmmm.... After scratching my head a bit, I started to wonder if it was a timing issue? I wondered if somehow the Sorcerer was eventually losing synch with the input data. Acting on this hunch, using Audacity I converted the sound file so it was 5% faster. No improvement. Then I tried 5% slower. Wow, I found that the load got further. Instead of falling over after about 45 seconds it was about 1.30 seconds or so. The volume also didn't seem quite as critical. Eventually after playing around and finding the limits I discovered that if I made the WAV files 8.5% slower I'd always get a successful load no matter how large the file (actually tolerance seemed to be between 7.5% and 9.5%). The more I moved outside those tolerance parameters, the quicker a load failed. Now the question is this. 1. Was it caused by an error in code in the MESS emulator, in that the sound files were created with the timing 8.5% faster than it should be OR.... 2. Is there something out of whack with the cassette interface in my machine (a cap out of tolerance maybe) which gives an incorrect timing/synch on load. Making the files 8.5% slower counteracted this fault, so a successful load was (always) accomplished? Any thoughts on this? At first I assumed it was just an error in MESS. That someone just got the timing wrong when writing the tape output routine. Thinking about it, now I'm not so sure? I couldn't seem to get any of the REAL tapes to load except for Martian Invasion (the shortest one). Happily as well as having a real tape, Martian Invasion was also in the binary archive. Before changing the speed, I could also get the Martian Invasion WAV to load with fine volume fiddling. So maybe it is the Sorcerer that's out of synch rather than MESS? I don't know, but it would be good to find out which one of the hypothese is correct. I might try to digitize the tapes. If I get nice square wavs, I'll see if I can slow these down by 8.5%. If I do, then can successfully load them into the Sorcerer, this would indicate that the problem is with my machine rather than MESS. Terry (Tez)

Hmm...there's a thought. I'll check that out. (I'll have to figure out how!) Terry (Tez)

I am _certain_ that I couldn't. My musical skill extend to determining 2 notes are differnt provided they are at least 3 octaves apart :-). Fortunately, I hae a 'scope and a frequency counter... -tony

On 17/06/2011 03:03, Terry Stewart wrote: Sorecerers are usually pretty good at reading tapes, so /something/ is definitely wrong. To see if its a problem with the sample rate, you could try recording something from the Sorcerer and see what happens when you play it back (at the same sample rate obviously!). From the monitor, you can just save a chunk of memory. Saving part of the ROM and loading it back is useful -- it always contains what amounts to pseudo-random data (rather than a whole lot of 0x00, or a whole of 0xFF, which you might have in RAM if you've not been running a program). A command to save 16 tape blocks would be SA TEST E000 EFFF Another thing you can try is connecting the EAR socket to the MIC socket, set it to SAVE something and watch the LED, which should go out while the Sorcerer is sending data. I've usually found that doesn't quite give the best results unless you use an attenuator, but at least it demonstrates that most of the hardware is correctly set up (or not!). The tech manual has a section on testing and if necessary adjusting the cassette interface circuitry, pages 31-33. There's also a write/read test program on page 31, which is short enough to enter as hex data. -- Pete Peter Turnbull Network Manager University of York

Hi Terry Your saying that 44000 was the rate it should have been played at and not 48000? Dwight

On 17/06/2011 22:21, Tony Duell wrote: They're useful for quite a lot of things. There's a neat design for a simple fixed-frequency short-pulse LED strobe, with construction notes, on the vinylengine website: http://www.vinylengine.com/diy-strobe.shtml http://downloads.nakedresource.com/download_centre/index.php?diy_strobe.pdf -- Pete Peter Turnbull Network Manager University of York

On 18/06/2011 18:53, Tony Duell wrote: The one I gave the link to, was for a similar purpose -- checking the speed of turntables for vinyl records -- though it could be used for anything you can put a 50/60Hz strobe pattern on. It's an elegant 2-IC design (a CD4060 and a CD4013) that runs off a PP3 and fits in a small standard box. -- Pete Peter Turnbull Network Manager University of York

On 19/06/2011 20:20, Tony Duell wrote: It uses a common crystal. You pick either a 3.2768MHz crystal for 50Hz or a 3.93216MHz for 60Hz; it's assumed that you need one or the other but not both (and generally that's true -- for checking motor speeds, you use the appropriate strobe pattern). It has an 8:1 duty cycle. As you say, you want a short flash. -- Pete Peter Turnbull Network Manager University of York

As usual I've written something on the experiences of getting software for the Sorcerer. It might be helpful to others and at the very least it means I won't forget what I did! http://www.classic-computers.org.nz/blog/2011-06-18-sorcerer-software-stock… Terry

On 19/06/2011 12:06, terry stewart wrote: After downloading the software you found, then downloading MESS, and then spending a frustrating couple of hours trying to get it to actually run (the docs are truly awful and it doesn't help that there are files either missing or in the wrong place) I found the same problem you did with the speed. I thought I'd found the magic setting to save the WAV file at 44100 instead of 4800, but that didn't help. And yet if I compare it to an MP3 that does work, the pitch seems almost the same, while slowing it down 8% to make it load (yes, that worked for me too) the pitch is way low compared to my MP3, and so says my oscilloscope too. The waveform is not great either. -- Pete Peter Turnbull Network Manager University of York

On 6/16/2011 8:35 PM, Terry Stewart wrote: The burner will almost certainly have a read mode. If it were me, and I realize this is sort of belt and suspenders thinking, I would read and display the suspected bad EPROM contents using the burner. You will likely see the same results, but it should definitely confirm (or question) your original very fine analysis. Later, Charlie C. <snip>

----- Original Message ----- From: "Terry Stewart" <terry at webweavers.co.nz> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Sent: Saturday, June 18, 2011 11:12 AM Subject: Re: More Sorcerer musings. Cassette interface issue,or a MESS programming issue? Well, I've spent a few hours today playing with my Dual Powered Standard Willem ROM burner. It seems reasonably straightforward. I've managed to read the contents of a few 27C256 EPROMS successfully. However, I couldn't read the contents of the BASIC-PAC 2k masked ROMS? I'm sure I have all the jumpers and switches right for a 2716, which I understand is an equivalant EPROM chip . All I got from all the ROMS was a repeating pattern of 0406 for 256 bytes then 1416 for the next 256 bytes and so on. I've checked and rechecked the settings and they seem right? Thinking I might have damaged the original ROMs by trying to read them I re-checked them again in the Sorcerer monitor. The data was still intact, except for the faulty ROM 3, which as before showed all zeros. I did read on a website somewhere that some masked ROMS could not be read by some EPROM programmers. Do you think that's the case here? I won't be able to burn any 27C16s to fix the ROM-PAC until the chips arrive in the post it's a waiting game for now. Terry

---snip--- Hi I prefer making an adapter. I use two stacked machine pin sockets and rewire things to match up with the selects. I also always remove the programming voltage. No sense blowing up a ROM because I accidentally asked the programmer to write to it. Some programmers leave the programming voltage on while reading as it is allowed on that EPROM, so be careful. Always isolate the programmng voltage pin. Sometimes, jumpering isn't enough to get the EPROM to work. The use needs another select that is high or low on the original ROM that isn't there on the EPROM. For these I've been know to take one of those tiny surface mount ICs to provide the logic needed and hot glue it in the center of another machine pin socket. One last thing. Make up a tag for the adpater you made to get the programmer to read the ROM. I like to use a simple diagram showing the levels of the select pins. Otherwise you end up with a pile of duplicate adapters. Also, I don't recommend bending a ROM pin enough to keep it out of a programmers socket. These are usually ZIF type sockets and you really have to bend it more than you'd want. If it is a ZIF socket, a small folded piece of paper is usually enough to isolate the pin without bending it. Dwight

Tonight I made up an "adapter" from a socket as per Dwight's recommendation, wiring it as Pete suggested. I tested the faulty ROM chip and a good one. Perfect! The faulty IC was all zeros and the good one contained code, just as I had seen in the Sorcerer itself. Diagnosis verified. Now to just wait for the EPROMs to arrive! Terry (Tez) ----- Original Message ----- From: "Terry Stewart" <terry at webweavers.co.nz> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Sent: Monday, June 20, 2011 1:21 PM Subject: Re: Sorcerer BASIC ROM-PAC ROM replacements

Thanks Tony. Pete, some of the guys of the Vintage computer Forum, have given me good advice of what to do here so I should be ok. Pete in particular as he's successfully replaced a ROM with an EPROM in his Sorcerer BASIC ROM-PAC, so he's had direct experience (and even has pictures of the mod). Terry (Tez)

I've written up the project thus far, for those who might be interested. http://www.classic-computers.org.nz/blog/2011-06-25-sorcerer-rom-pac-fix-pa… I'm just hoping that I can get this Willem to burn the 27C16s properly. I've got to wait for my UV eraser to arrive though to try again. Terry (Tez)

On 02/07/2011 05:55, terry stewart wrote: Well done! Have you tried erasing and reprogramming the 27C16s that didn't quite work before? I wonder if one or both has a stuck bit, or just wasn't properly erased. Or maybe they require a slightly different programming voltage to what you used. Some EPROMs need 25V or 21V, but newer types often need 13V or 12V. And newer types typically want a shorter programming pulse, or a series of short pulses. -- Pete Peter Turnbull Network Manager University of York

Terry, A great write up and an interesting read. Huw Davies | e-mail: Huw.Davies at kerberos.davies.net.au Melbourne | "If soccer was meant to be played in the Australia | air, the sky would be painted green"

I'm not sure it is an exact equivalent. The Sorceror ROM Pac seems ot ahve jumper links associated with each ROM chip (these are shown on the schematic with no explanation!). From what I rememebr, one set of connections for those links will let you use 2716s, but there are, of ocurse, orther arangements of links for chips with slightly differnet pinouts. In generaly, the +5V, grpound, data pins and the lower order address lines are onm the same plins for EPROMs, masked ROMs, etc. But things lik chip selects, and the higher address lines may move around a bit. What I would do is look at the ROM Pac PCB that you took thise ROMs from, and work out just what signal is on each pin of the ROM. You may want to trace the conenctions with an ohmmeter. Of coruse the schematic is very useful too here. You then have a pinout of the mask ROMs. You cna compare tht against the known pinout of a 2716 to see whatis different. if you replace the defective ROM with a 2716, you may have to reconfigure the links to get the signas on the right pins. Foprtuantely, there are separate links for each ROM chip, so you can have a mixture of types on the board. -tony

I got it with my Sorceror. I think I paid \pounds 10.00 for the lot, but that's when classic computers were actually affordable :-) I've never seen a secod one (or indeed another Sorceror). Excellent!. Wanting to learn is always a Good Thing, and one reason for doing battle with a classic computer. I have yet to see a stupid question :-). In other words, ask away and I am sure somebody will help you. Most likely it is :-(. My expeirence is that while LSI devices are more reliable than the equivleant circuit made from MSI chips or discrete components, I do find that as the complexity of the IC goes up, the reliabiltiy goes down. In other words, a single-chip ROM is going to be mroe reliable than decoding the addresses and logically ORing the apporpirate termis using doiode and TTL, but the ROM chip will be less reliable tyhan the (much simpler) TTL chips used as the address decoder in the cartridge. My thought is roughly what yopu suggested. If you find a way to get the machine inot a machien code monitor with the ROM PAC in place, I would suggest looking at the address range occupied by each of the chips. An unadresssd chip will probasbly rread as all $FFs or something like that. So if an entire block reads aas $FF, then either that ROM is defective, or it's not being slected. a Loigc probe on the chip select pin will probably tell you which is the case. Hoiwever, it's not uncommon for a ROM to fail in such a way that it never outputs anything (just leaves the data lines floating, as though it's not there at all). Of course if the chip selection logic -- the little chips in the ROM PAC -- fails, you get the same behaviour. -tony

Strangely, my eyesignt is not good enough to see a thing the size of a Sorceory 70 miles away (even if there was nothing in the way). -tony

Err, no. That's a _picture_ of an Exidy Sorceror (I assume). I've seen plenty of such pictures. I do not doubt that you own a Sorceror, or that other people here do to. But the only Sorceror I've seen 'in the silicon' is the one I own. -tony

On 15/06/2011 19:55, Adrian Graham wrote: Even closer to where my current one came from (about 3-4 miles from where Tony lives) and not much more from where my original one went when I sold it in the early 80s. -- Pete Peter Turnbull Network Manager University of York

On 10/06/2011 12:47, terry stewart wrote: Welcome to the ranks of Sorcerer owners :-) Images of the four BASIC ROMs are on my website, and you'll find them also on some other Sorcerer websites such as http://www.trailingedge.com/exidy/ I think I also have a PCB layout for a ROM-PAC somewhere -- not the original, but one I drafted many years ago to use different EPROMs. However, it's easy enough to re-jumper the sockets in the ROM-PAC for different EPROMs, and more than one listmember has a Sorcerer with a PAC I've repaired that way. The original ROMs are mask ROMs, of course, but Exidy designed the PAC to take various different ICs. -- Pete Peter Turnbull Network Manager University of York

On 11/06/2011 13:16, terry stewart wrote: The Sorcerer Technical Manual has the information, but if you don't have a copy you can download it from David Williams' Trailing Edge site. http://www.trailingedge.com/exidy/hwref.pdf You want to look at the schematic for the ROM PAC which is on page 43 in the PDF file. Exactly what you need to do depends on your EPROM; I used a 2732 last time (the mask ROMs are each 2K x 8bit, making 8K bytes total). It's a while since I looked for software. I only found a couple of items last time, and one of those was corrupt. Any pointer you can give me? But I've found the Sorcerer is very good at handling audio files, and I regularly use MP3 files of two or three demo programs, fed from my iPod or iPhone headphone jack. -- Pete Peter Turnbull Network Manager University of York