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Tape Interface

Tape Interface

antiquekid3 said:
I have a SWTPC 6800 with the tape interface, and instead of recording to a tape deck, I tried recording to my MacBook using Audacity. After recording, I exported the file as an MP3 into iTunes. I have had no problems so far reading an MP3 file and sending it to the SWTPC. I don't know if the Cortex uses the 300 baud Kansas City standard or not, but if it does, it's just having to distinguish between two frequencies, which aren't that hard to reconstruct from an MP3 file.

I think it'd be nice to have a website devoted to these sound files for different machines, along with the source code.

Kyle
Click to expand...

I don't know what standard the Cortex uses but I've got Audacity on my PC, so I'll give it a go - Thanks for the info
 
I'm going to try and get the rest of the documentation folks have provided up onto WHTech over the next few days. RL has been keeping me waaaayyy tooo busy of late. . .no time at all for my hobby. :(
 
After a careful look, I am now busy inputting the Cortex Fig-Forth manual pages into a single, edited document. I should have it finished before the weekend and then I can put it up on WHTech. The job and school had me waaaaayyyyy too busy this fall, but the tempo is down now, so I have time for my hobbies again :)

I wonder if NigeThe Hippy had any luck reading the ROMs for it?
 
roms- - I have done a bit, the eprom programmer is at this moment in pieces in front of me, it puts the right programming voltage on the right pin at the right time etc, but for some reason the 5v looks too low. I'm tracing through the pcb to work out why.
I'm still too nervous to put the original forth eproms in the machine before it's 100%. There's a possible alternative (old school) solution on the near horizon, I'm keeping my fingers crossed!
 
I put a nice PDF of the Cortex FIG-Forth manual up on WHTech today, along with instructions on using the TMD2797 Disk Controller chip, the TMD9929 RGB interface, and the V9938 mod. Many thanks to ANDYP and TMS9995 for taking the time to make the original scans. I took the FIG-Forth manual and redid it to make it the highest quality manual possible (like I did for the original Cortex BASIC manual a while back). I'll probably do the same for the MDEX manual next. . .
 
I'm now the proud owner of a decent 1980s eprom/pla/prom/uC burner, (Stag PPZ) with quite a few pods. I pick it up monday, apparently it nearly all works (although I can pretty well guarantee that the 2564 will lie just outside that nearly)
 
well as luck would have it, the chap tested it on a 2564, and it was fine
I've uploaded the 2 forth roms, although I'm not sure what order they should go in (if at all) I suspect the "red" one is second as it's only 1/2 full.
files attatched, in intel hex. (additional ".txt" added in order to upload)

Have a look, & see if it makes sense.


Incidentally, I'll get the 3 O/S roms going as soon as I've figured out why I'm not transferring data the other way
 

Attachments

  • forth rom red.hex.txt
    24.5 KB · Views: 1
  • forth rom green.hex.txt
    24.5 KB · Views: 1
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nige the hippy said:
well as luck would have it, the chap tested it on a 2564, and it was fine
I've uploaded the 2 forth roms, although I'm not sure what order they should go in (if at all) I suspect the "red" one is second as it's only 1/2 full.
files attatched, in intel hex. (additional ".txt" added in order to upload)

Have a look, & see if it makes sense.


Incidentally, I'll get the 3 O/S roms going as soon as I've figured out why I'm not transferring data the other way
Click to expand...

Great news.

According to the original installation instructions, the eprom marked >0000 goes into SOCKET IC47 and the eprom marked >2000 into SOCKET IC46.
From memory I think they are numbered - (very small in biro)
I've had a look at your attached files but have to confess they don't mean a lot to me.
I've got a copy of the memory map, I'll send this to you on seperate e-mail, it might help.
 
No chance to look at the memory map, but what you say now makes sense - I ought to rename the files, green is >0, red is >2000.
And I've now written the OS eproms.
I'll get them in the post ASAP.
 
Way to go guys!

I have attached FORTHROM.zip which contains FORTHROM.BIN. If you save this into the emulator directory as CORTEX.BIN (having renamed the original as CORTEXROM.BIN) you can check it out using the emulator! Only gave it a quick once-over, but seems to work! 27 years after I got the computer I've seen something new on it. Thanks to all.
 

Attachments

  • FORTHROM.zip
    10.6 KB · Views: 1
Excellent news! Now we have FIG-Forth ROM dumps for both the emulator and the hardware! Thanks to everyone, and especially to Andyp for keeping his copy all these years!
 
Maybe we can get Cybernaut energized to scan the documentation items he mentioned having that were missing from the archives as well. At this rate, in a year or so we'll have everything there ever was for the Cortex preserved online. . .
 
Just received my shiny new Eproms from "Nige the Hippy" and am about to install them.
Just want to ensure i put the correct Eprom in the correct socket.
The sockets are labeled 45, 46 + 47 and the Eproms are labeled 1,2 and 3.
I was going to put them in number order then I realised that the Forth Eproms seem to number the other way around i.e. 1st Eprom in skt 47.
Can anyone advise?
Thanks
 
Had a quick look at the circuit diagram and IC47 is the first, IC46 is the second and IC45 is the third. Good luck and let us know you have a working Cortex Basic!
 
tms9995 said:
Had a quick look at the circuit diagram and IC47 is the first, IC46 is the second and IC45 is the third. Good luck and let us know you have a working Cortex Basic!
Click to expand...

Thanks for the info. I put the new eproms in and no luck! - All I got was a constant tone and the "MEM" LED lit.
I then decided to fit my Forth eproms and got similar results. After a few resets I got the LEDs to stabilize and ended up with the "RUN" LED lit but then couldn't get any text prompt on the flickering video output. The whole set-up seems to be a bit unstable and the LEDs keep changing state if I move the chassis. I'll have to check the supply voltages and hunt around for loose connections etc. I seem to remember that the video output was always a bit unreliable.
I like a challenge !!!
 
I've just had another look at my dead Cortex and have got a few questions:

What is the normal sequence for the front panel LEDs after a reset - I can't remember and can't find my original guide, but I'm assuming that a healthy Cortex just has the "BASIC" LED lit if all is OK. Mine seems to mostly display a dim / flickering "RUN" led and constant "MEM" led, if this means anything.
I've checked my PSU output and measured: + 4.3v, +11.73v, -12.1v using the 0 volt line on the PSU output connector. - ( For some strange reason if I measure the voltages using the chassis earth, I get + 4.94v, +11.92v, -12.02v ).
Does anyone know what the tolerances are on these voltages? -- I suppose I could get a PSU from an old PC just to be sure.
Last question - When I put it together in the 1980's, I decided to use dual-contact sockets in every IC position, in case I had problems and needed to replace any ICs.
Do you think that the contacts on these socket could have oxidised over 27 years and maybe I should remove and re-seat each IC in-turn, or would I be wasting my time.

Any advice would be appreciated.
 
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andyp said:
I've just had another look at my dead Cortex and have got a few questions:

What is the normal sequence for the front panel LEDs after a reset - I can't remember and can't find my original guide, but I'm assuming that a healthy Cortex just has the "BASIC" LED lit if all is OK. Mine seems to mostly display a dim / flickering "RUN" led and constant "MEM" led, if this means anything.
I've checked my PSU output and measured: + 4.3v, +11.73v, -12.1v using the 0 volt line on the PSU output connector. - ( For some strange reason if I measure the voltages using the chassis earth, I get + 4.94v, +11.92v, -12.02v ).
Does anyone know what the tolerances are on these voltages? -- I suppose I could get a PSU from an old PC just to be sure.
Last question - When I put it together in the 1980's, I decided to use dual-contact sockets in every IC position, in case I had problems and needed to replace any ICs.
Do you think that the contacts on these socket could have oxidised over 27 years and maybe I should remove and re-seat each IC in-turn, or would I be wasting my time.

Any advice would be appreciated.
Click to expand...

The power-on sequence takes about a second and involves mainly the RUN LED being lit until the initialisation is complete whereby it will sit at IDLE with the BASIC LED flashing about once per second. The MEM LED indicates the Memory Mapper has been turned on with a CKON instruction and doesn't sound normal for powering on.

There should be a good solid 5V measured on the board (eg across the power pins of any IC). Maybe you've got a bunch of ripple due to bad PSU capacitors? As far as the ICs go, I would definitely recommend reseating them as they do tend to oxidise up.
 
Ditto, I would also add check the rectifier is happy, it sounds to me like terrible ripple is the first problem to look at.
 
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