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Messages - BruceTanner

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Hardware / Re: SymbiFace3 is near your Enterprise...
« on: 2020.February.19. 23:59:38 »
Sadly, yes! Some pics here https://enterpriseforever.com/maintenance/glitch-on-rd/

My problem is in the WIZ W5300 network chip - it has an internal FIFO with a auto-incrementing data pointer. So to read a received frame, for example, you just do lots of reads, and the pointer auto-increments to the next byte. I interfaced it using I/O, so it happened when the I/O address was decoded and there is a /RD cycle. The main glitch happens when /RD is low :roll: so the W5300, being a modern fast device, sees 2 read cycles and increments the FIFO pointer twice. Not every cycle, just occasionally.

I have seen the glitch on a EP with no expansion attached - you just need to look at /RD on a scope that can trigger on a short high pulse (basic Rigol scope in my case). My early EP64 seems worse than my later EP128s.

Having got to the bottom of this, Zozo pointed out that a few EXDOS cards have a factory-fitted bodge on the back. When I looked, it was a R and a C on the /RD line going to the EPROM, and it successfully removed the glitch! I could also see it at the WD1770 but it works...so must happen at a slightly different point in the cycle. Or the WD1770 is too slow to notice the glitch. Or a double read doesn't matter to it.

@gflorez sorry, I have accidentally hijacked your thread :oops:


Hardware / Re: SymbiFace3 is near your Enterprise...
« on: 2020.February.19. 21:52:39 »
Ok thank you.

My reason for asking is that I was wondering if you had found the glitchy signals, /RD particularly, that have caused me many many problems! So far no one else has reported seeing them on a 'scope, so occasionally I start questioning my sanity! :smt120 Then I remember the factory glitch mod that some EXDOS cards have...

Worse on early EPs is familiar! And so is worse on memory than I/O! And so is being affected by the 245!

One lesson I learned (maybe a proper h/w designer would have already known): use a real LS245, not a CMOS HCT245, because CMOS inputs left floating (eg on the tri-state data bus) are bad - can cause the chip to oscillate, and I have seen this. Even on a chip designed to interface to busses. :roll:

In my case the h/w had auto-incrementing registers so was very sensitive to glitches. On a memory-type interface if a glitch causes a double read or write, the device will just stop & start outputting or reading the data again, and nothing will go wrong unless the glitch occurs at just the wrong time.


Hardware / Re: SymbiFace3 is near your Enterprise...
« on: 2020.February.19. 18:02:21 »
Yes. With 74ls245 socket.
Its possible to make an 245 jumper. With the 245 jumper breakout.
See in the right corner of the pcb
Can I ask what the 245 issue is?

Summaries from the Hungarian topics / Re: Interview with Nick Toop
« on: 2020.February.16. 14:59:05 »
But seems he want to forgot Enterprise forever :cry: Something went very-very wrong at the companies crash. As he wrote it: "one of the saddest periods of my life and I do not like to think about it."
I afraid he became hating the Enterprise forever and never want to hear anything about it :cry:

Remember: I tried to make interview with he at 2008, but after the first contact ("Yes, I'm that Nick") never answered anything :cry:
Yes it is very sad. This only occurred to me a few days ago: but I can see how he might have received all of the blame by "various people" high up in Enterprise Computers and/or Intelligent Software for the delays to the initial launch of the EP, which as we know were largely caused by Nick chip problems (which, I would say, were caused by pushing the available ASIC technology to its limits, not by bad design.) Apart from the delays, each revision of the Nick chip cost someone a lot of money, and whoever that was would not have been pleased. He must have been under a lot of pressure at the time.

Hall of Fame / Re: Q&A with Bruce Tanner (IS-BASIC writer)
« on: 2020.February.12. 00:12:30 »
Nice to meet you ... errr, again, since we may well have bumped into each other when I was doing my summer in the IS basement.
Yes we must have bumped into each other! I spent most of my time upstairs though, in the front room. But came downstairs very frequently because that is where the coffee machine was.

Gawd, we were all so young back then! ;-)
Yes, and so old now :lol:

I used M80/L80 today (new version of EXDOS coming...) :lol: Instead of a 4MHz processor with 64Kb RAM, these days it is from a Linux terminal via a z80 emulator on a 7-core processor running at  2GHz with 16Gb RAM.  One of the files prints out "* warning: this takes 20 minute to assemble *" when you assemble it, but now it takes about 1/2 second :ds_icon_cheesygrin: :lol: There goes my excuse to visit the coffee machine!

Yet sitting at the Linux terminal is not that different from sitting at IS-DOS. If I ran Windows instead, most of the commands would even be the same :mrgreen:

Hardware / Re: Fischertechnik Robot Interface 30520.
« on: 2020.February.10. 12:54:48 »
I hope the IC is not damaged too, it might be difficult to get a new one.

I was interested to see what that IC does, but I could not find any information.

But then I discovered the part number is TLE4201S1, not TLE420ISI as it looks (ie. one-sss-one at the end.)

So now that I have found it, I might as well post the datasheet here in case you do not have it. On page 554 (:lol: it starts at page 551 :lol:) there is an example circuit with four diodes...

Hall of Fame / Re: Q&A with Bruce Tanner (IS-BASIC writer)
« on: 2020.February.10. 11:56:46 »
Welcome to the forum, and thank you for posting those! It is a *long* time since I have seen those company letterheads, and they still seem strangely familiar - even the telephone numbers.

Or perhaps he was just being overly optimistic in June 1986 ... has there been any evidence posted that he didn't get the contract after all?
I don't think there was ever an actual signed contract, but if there was, it all fell through before any work was done!

IS Systems was only Robert Madge and 4 ex-IS engineers (one of them me!) While I finished off Z80 work from IS, the others looked into networking while Robert Madge went around trying to find us work, one possibility for that being MSX-DOS 2. Not being able to get any development contracts, we started making our own token ring networking cards and we became Madge Networks, and I did not write any more z80 code for nearly 30 years!

This was IS Systems (Robert Madge is the one in front of the tree):

Other topics / Re: Switching Between Keyboard Languages?
« on: 2020.January.14. 09:28:00 »
Am I correct in thinking that although the letters/words are written right-to-left, numbers are written left-to-right?

Other topics / Re: Switching Between Keyboard Languages?
« on: 2020.January.12. 17:36:38 »
But making the Arabic characters type right-to-left would be a bit more of a challenge!

Programozás / DRVTEST
« on: 2020.January.07. 14:25:32 »
Itt a DRVTEST, egy kis alkalmazás hajlékonylemez-meghajtók és EXDOS kártyák teszteléséhez, diagnosztizálásához és vizsgálatához.

Azért írtam, hogy segítsen az EXDOS 3 fejlesztésében, valamint segítsen a öreg hardverek életbentartásában.

A DRVTEST.COM betölthető a BASIC-ből, vagy futtatható IS-DOS parancsként, vagy a DRVTEST.ROM behelyezhető egy ROM-ba, és a következővel indítható :DRVT.

Egyes helyeken meglehetősen technikai, de a H gombbal elérhető HELP leírás. Vagy csak válasszon meghajtót A vagy B gombbal, majd nyomja meg a T gombot a Tesztek futatásához meghajtó vizsgálatára!

Programming / DRVTEST
« on: 2020.January.07. 14:20:59 »
Here is DRVTEST, a little application for testing, diagnosing and investigating floppy disk drives and EXDOS interfaces.

I wrote it to help with EXDOS 3, and also to help keep vintage hardware running.

DRVTEST.COM can be loaded from BASIC or run as an IS-DOS command, or DRVTEST.ROM can be put in a ROM and started with :DRVT.

It is quite technical in places, but you can press H for help. Or just select a drive with A or B and then press T for Tests to exercise your drive!

Letöltések / Downloads / DRVTEST
« on: 2020.January.07. 14:04:49 »
DRVTEST: floppy disk drive testing and diagnostic tool.

Load DRVTEST.COM from BASIC or IS-DOS, or burn DRVTEST.ROM into a ROM and start with :DRVT
Press H for explanation of status letters and key presses.

Hardware / Re: Fischertechnik Robot Interface 30520.
« on: 2020.January.02. 16:26:00 »
these case the A register sent to high byte. On ZX Spectrum used this is for the keyboard handling:
LD A,n
IN A,(0FEh)
I didn't know that! Thank you for today's lesson :lol: :bow:

Hardware / Re: Fischertechnik Robot Interface 30520.
« on: 2020.January.02. 09:10:01 »
If it is any help, this is EXOS's parallel printer output routine:
Code: [Select]
WC_PAR:: LD A,B ;Send data to parallel output port
CP ?STOP## ;Check for STOP key interrupt
LD A,.STOP## ;Load error flag
LD A,(PORTB5) ;Fetch map of port B5
OR 00010000B ;Force STROBE low
OUT (STROBE_PORT),A ;Send data strobe
AND 11101111B ;Reset STROBE high (normal state)
OUT (STROBE_PORT),A ;Send to port
XOR A ;Clear accumulator
RET ;Back to kernel
DATA_PORT and INPUT_PORT are both 0B6H and STROBE_PORT is 0B5H.

Clearly on the CPC the value in B is important when you do an OUT (C),r or IN r,(C) - on the EP the value in B is not used (the instruction should have been called OUT (BC),r and IN (BC),r!) If you do an OUT (n),A or an IN A,(n) as the EXOS code does then 0 is used as the high byte of the port address, so the CPC code has to avoid using that form of OUT and IN. Even so,
Code: [Select]
SHOUT: LD BC,#EFOO ;pointer to printer port
LD C,A ;use C as work register
is just wasting time and space!

Programozás / Re: EXDOS
« on: 2019.December.30. 00:28:06 »
Code: [Select]
:MD e:ujmappa
:COPY a:ujmappa e:ujmappa

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