|
Homebrew Equipment A place to show, design and discuss the weird and wonderful electronic creations from the hands of individual members. |
|
Thread Tools |
9th Apr 2019, 6:35 am | #1 |
Rest in Peace
Join Date: Jul 2011
Location: Bridgnorth, Shropshire, UK.
Posts: 787
|
My 'ASR 33' terminal
I just thought I'd reveal my latest computer-related creation. It's a terminal, complete with 25x16 character display and a card reader/punch
It runs at the lightning speed of 110 baud and is so dumb that it qualifies for the description 'decerebrate'. I can once again experience that frustration at watching characters appear at the sedate pace of ten per second |
9th Apr 2019, 6:48 am | #2 |
Moderator
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,903
|
Re: My 'ASR 33' terminal
Future enhancements to include sound effects, the smell of the oil and and the smell of a hot motor?
David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done |
9th Apr 2019, 6:59 am | #3 |
Rest in Peace
Join Date: Jul 2011
Location: Bridgnorth, Shropshire, UK.
Posts: 787
|
Re: My 'ASR 33' terminal
Hi David,
Well, maybe not the oil! But I did seriously consider playing out samples when printing, returning the carriage, etc. In the end I just added a little keyboard 'bleep' to acknowledge each key press. Samples become tiring when they're identical every time, and I wouldn't go to the trouble of making dozens of them all with slight variations. |
10th Apr 2019, 9:22 pm | #4 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 14,010
|
Re: My 'ASR 33' terminal
How lovely!
Stylistically, it sort-of reminds me of the Texas Instruments "Silent-700" thermal-printing-terminal-with-acoustic-coupler-and-cassette-storage I used in the late-70s to prepare programs for submission via dialup to the University of Manchester's CDC7600 mainframe. |
11th Apr 2019, 10:16 am | #5 |
Octode
Join Date: Nov 2004
Location: Hebden Bridge, West Yorkshire, UK.
Posts: 1,885
|
Re: My 'ASR 33' terminal
Lovely! I keep meaning to buy/make a paper tape reader!
|
11th Apr 2019, 3:54 pm | #6 |
Rest in Peace
Join Date: Jul 2011
Location: Bridgnorth, Shropshire, UK.
Posts: 787
|
Re: My 'ASR 33' terminal
Thank you G6Tanuki, Dominic!
I must admit I was going for the 'cuteness factor'. I think its first application will be connection to a full emulation of NIBL on an SC/MP, using the original tty routines. The only shortcoming may be the inability to stop the 'paper tape reader'. NIBL turned a flag on and off to control a 'reader relay' to throttle the reader. |
11th Apr 2019, 6:17 pm | #7 |
Hexode
Join Date: Mar 2014
Location: Fareham, Hampshire, UK.
Posts: 482
|
Re: My 'ASR 33' terminal
Smashing, Karen, I love it. Brilliant project.
__________________
Failing to prepare is preparing to fail ... |
23rd Apr 2019, 9:20 pm | #8 |
Rest in Peace
Join Date: Jul 2011
Location: Bridgnorth, Shropshire, UK.
Posts: 787
|
Re: My 'ASR 33' terminal
The first host for my 'ASR 33 terminal' is shown below - a NIBL BASIC computer running under an SC/MP emulation implemented on a PIC.
I've made NIBL computers like this before, but this one is a bit special. In the past I have implemented serial I/O in PIC code, and exchanged characters with NIBL by creation of extra SC/MP pseudo instructions. This one implements the serial routines in SC/MP code, exactly like the original NIBL system. The PIC implements a cycle perfect emulation to accomplish this. In fact, the PIC can be used as an SC/MP in itself, though it is nowhere near pin compatible. It can address 64K using its port pins. I've only used 32K of this space to access a 32K static RAM. I've arranged that the NIBL interpreter is copied into low RAM during initialisation. It is then write protected. Anyway, the upshot is that this computer can list very much faster than it can load. So if I just play back its own listing to it, it will fall way, way behind. I was hoping I could simply suppress the line feed characters to provide an adequate pause between lines, but it is not enough. NIBL requires between 310msec and 520msec to load a new line! In original application, NIBL used one of its flags to control a 'reader relay' in a teletype. This enabled the paper tape reader to be stopped while NIBL digests each line that is loaded. There is no way I'm going to make a cassette mechanism 'stop on a sixpence' like that so... I am adding a playback FIFO. I will use the reader relay flag as a hardware flow control signal, rather like RTS is used in RTS/CTS handshake that became standard (though departing from the original intention of these control lines). So, I'm building something almost as sophisticated as the NIBL computer itself to prevent overrunning it during cassette playback! But I've convinced myself that there is a higher purpose here. Either that or I have truly gone over the edge! |
25th Apr 2019, 7:33 pm | #9 |
Triode
Join Date: Feb 2019
Location: Battle, East Sussex, UK.
Posts: 22
|
Re: My 'ASR 33' terminal
Ah ha - SC/MP - my first 'toe in the water' computer back in the 1970's
I have a skeletal paper tape reader if anyone wants it for the price of the postage - also rather a lot of 1" paper tape (email me as I don't come here every day andrew <at> mawson <dot> org <dot> uk ) |
25th Apr 2019, 7:55 pm | #10 |
Triode
Join Date: Feb 2019
Location: Battle, East Sussex, UK.
Posts: 22
|
Re: My 'ASR 33' terminal
Have same pictures
|
26th Apr 2019, 10:02 am | #11 |
Triode
Join Date: Feb 2019
Location: Battle, East Sussex, UK.
Posts: 22
|
Re: My 'ASR 33' terminal
The tape reader has now been re-homed - so that's one more bit of junk disposed of - thanks Karen
|
26th Apr 2019, 1:43 pm | #12 | |
Dekatron
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 16,536
|
Re: My 'ASR 33' terminal
Quote:
Wenlock, perhaps?
__________________
....__________ ....|____||__|__\_____ .=.| _---\__|__|_---_|. .........O..Chris....O |
|
26th Apr 2019, 2:13 pm | #13 |
Octode
Join Date: Nov 2004
Location: Hebden Bridge, West Yorkshire, UK.
Posts: 1,885
|
Re: My 'ASR 33' terminal
Ah too slow! I've been after a tape reader for a while now. If anyone else has one kicking about I'd me interested - though Karen can probably make more immediate use of it!
D |
16th May 2019, 12:45 am | #14 |
Octode
Join Date: Apr 2018
Location: Newbury, Berkshire, UK.
Posts: 1,287
|
Re: My 'ASR 33' terminal
I remember "back in the day" that computers could be made to outout NUL (0x00) characters after the linefeed during listing to allow the computer time to process the line. I suppose you could try this, if its possible to get the sc/mp to ignore NUL characters and not lose sync with the serial stream.
On the DG Nova I used at school there was a seperate PUNCH command that acted exactly like LIST except it punced out the NUL characters. Perhaps you could add a command to NIBL to wait a half second between lines? |