EPiC - A new 68k multi-processor motherboard project
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mercury0x000d
Joined: Tue Jun 03, 2014 2:40 pm Posts: 127
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carronjack wrote: Any more news on this? Regards Carronjack Yes! I've been sourcing 68000s from multiple places online, but it occurred to me I have no way to test them as they arrive, as I have no actual components to EPiC set up yet. To fix that, I needed a simple tester which could put the chips in "free run" mode. The ideal tester would have a ZIF socket to allow you to painlessly swap multiple chips without wear and have a variety of clocks which would be selectable to test the chip's performance at varying speeds. An external clock connection would be helpful too, for future expansion. It would be able to be powered from a simple ATX power supply (since I have tons of those lying around and they do a great job of providing simple clean power at 3.3V, 5V and 12V) and would have an array of LEDs to show processor activity on the address bus, along with indicators for the FCx lines of the 68000. In other words, something like this...
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Sat Jun 03, 2017 7:52 pm |
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carronjack
Joined: Mon May 22, 2017 12:11 am Posts: 23 Location: NW Scotland
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Looks like good stuff, I've building 68xxx machines since 1985, bought my first one from Jameco. Had to pay import tax ( bugger ). Wire wrap is a no no at these speeds, but you have a pcb now. I have been using 6U style eurocard, random wiring in Kynar 0.30 point to point, can't remember the website but with high speed busses auto routed side by side crosstalk is a big problem. Currently running a Coldfire MCF5208 @ 200Mc/s, that's how old I am, don't use hertz. Bus speed 100 megs, don't use dram. Whats the point in using memory that forgets, you might as well use a goldfish. For your interface logic 74AC is plenty fast enough, and as a general rule 68xxx can be overclocked by 25% Go for a 68EC075 overclock it and get a big heatsink, if you need an FPU 68882's can be got up to 50+ Mc/s. Don't forget to tie your TDO TDI to GND or VCC otherwise it will go into JTAG mode and unless you've got a simulator. Can't remember offhand what's high and low, but if you reply I'll lookup what works. One more point don't apply 5V to the 68060 it will destroy the chip.It's 3.3V only with 5V tolerant I/O ( i.e. Address and Data lines ) ASC do static ram 512kx8 55nS access 4 off give you 2 Meg enough to be going on with Why do you need an MMU, I realise you are a software guy, the whole thing grinds to a halt when you get page fault. Simple don't access non-existant memory. Plus you have DTACK or DSACK0 DSACK1 on the 060 put that ORed signal into a counter say 16 ticks then generate an interrupt from the overflow of the counter. Keep going I know its quite steep learning curve at first
Best Regards Ian Hughes ( carronjack) Computer Hardware Engineer ( Retd. )
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Sat Jun 03, 2017 8:43 pm |
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mercury0x000d
Joined: Tue Jun 03, 2014 2:40 pm Posts: 127
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carronjack wrote: Looks like good stuff, I've building 68xxx machines since 1985, bought my first one from Jameco. Had to pay import tax ( bugger ). Wire wrap is a no no at these speeds, but you have a pcb now. I have been using 6U style eurocard, random wiring in Kynar 0.30 point to point, can't remember the website but with high speed busses auto routed side by side crosstalk is a big problem. Currently running a Coldfire MCF5208 @ 200Mc/s, that's how old I am, don't use hertz. To what would that roughly equate in MHz? carronjack wrote: Bus speed 100 megs, don't use dram. Whats the point in using memory that forgets, you might as well use a goldfish. ![Laughing :lol:](./images/smilies/icon_lol.gif) carronjack wrote: For your interface logic 74AC is plenty fast enough, and as a general rule 68xxx can be overclocked by 25% That applies to the entire family? carronjack wrote: Go for a 68EC075 overclock it and get a big heatsink, if you need an FPU 68882's can be got up to 50+ Mc/s. What is the 68075? Never heard of that one. carronjack wrote: Don't forget to tie your TDO TDI to GND or VCC otherwise it will go into JTAG mode and unless you've got a simulator. Can't remember offhand what's high and low, but if you reply I'll lookup what works. I'd appreciate that! carronjack wrote: One more point don't apply 5V to the 68060 it will destroy the chip.It's 3.3V only with 5V tolerant I/O ( i.e. Address and Data lines ) ASC do static ram 512kx8 55nS access 4 off give you 2 Meg enough to be going on with Why do you need an MMU, I realise you are a software guy, the whole thing grinds to a halt when you get page fault. Simple don't access non-existant memory. Plus you have DTACK or DSACK0 DSACK1 on the 060 put that ORed signal into a counter say 16 ticks then generate an interrupt from the overflow of the counter. Keep going I know its quite steep learning curve at first
Best Regards Ian Hughes ( carronjack) Computer Hardware Engineer ( Retd. ) Thanks for the input! ![Smile :)](./images/smilies/icon_e_smile.gif)
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Sat Jun 03, 2017 10:00 pm |
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carronjack
Joined: Mon May 22, 2017 12:11 am Posts: 23 Location: NW Scotland
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Hi re your questions Mc/s = Mhz so roughly MCF5208 is doing 160 MIPS sorry about the typo I meant MC68EC060RC75 There are 2 signals MDIS bar, CDIS bar or -MDIS -CDIS i.e.active when they are low 0V tie these low until your program is running to your satisfaction, then bring them up to Vcc 3V via a 1k resistor.The cache branch predictor can be very indeterminanistic. meaning a different # of clock cycles between one run and the next. I will look up the pin settings for you tomorrow for the JTAG interface and post them here. These were derived after much pain and heartache. RE the the clock speed, yep pretty much I've run 16Mhz ST68000 @ 28Mhz no probs ran a MC68882 at 60mhz till my power supply failed Interface logic keep it simple, no CPLD's or PALS you can build anything you need out of 74AC logic Keep the faith It's there to be done, 'cos we can
Best Regards Ian Hughes ( carronjack )
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Sun Jun 04, 2017 3:30 am |
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mercury0x000d
Joined: Tue Jun 03, 2014 2:40 pm Posts: 127
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carronjack wrote: Hi re your questions Mc/s = Mhz so roughly MCF5208 is doing 160 MIPS sorry about the typo I meant MC68EC060RC75 There are 2 signals MDIS bar, CDIS bar or -MDIS -CDIS i.e.active when they are low 0V tie these low until your program is running to your satisfaction, then bring them up to Vcc 3V via a 1k resistor.The cache branch predictor can be very indeterminanistic. meaning a different # of clock cycles between one run and the next. I will look up the pin settings for you tomorrow for the JTAG interface and post them here. These were derived after much pain and heartache. RE the the clock speed, yep pretty much I've run 16Mhz ST68000 @ 28Mhz no probs ran a MC68882 at 60mhz till my power supply failed Interface logic keep it simple, no CPLD's or PALS you can build anything you need out of 74AC logic Keep the faith It's there to be done, 'cos we can
Best Regards Ian Hughes ( carronjack ) Good info, thank you! Have you ever got a 68060 to freerun? I've been looking into what needs held high and low to make it happen. Here's what I've worked out so far: Code: transfer attributes cla 1 tt0, tt1 float? tm0 - tm2 float tln0, tln1 float upa0, upa1 float r/w float siz0, siz1 float lock float locke float ciout float bs0 - bs3 float
master transfer control ts tip sas
slave transfer control ta tra tea tbi tci 0
bus snoop control snoop
bus arbitration control br bg bgr bb btt
processor control cdis mdis 0 rsti rsto float
interrupt control ipl0 - ipl2 1 ipend float avec
status and clocks pst0 - pst4 clk clken
test jtag 0 tck 0 tms 1 tdi 1 tdo float trst 0
thermal resistor connections therm0, therm1 float
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Sun Jun 04, 2017 7:29 am |
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carronjack
Joined: Mon May 22, 2017 12:11 am Posts: 23 Location: NW Scotland
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Right found my 060 circuit diagrams in my very cluttered shed TDI and TDS tied together up to Vcc via 1K resistor. -TRST TCK -JTAG put to GND - in front of the signal says it's active low. That will stop it going into boundry scan. I need to look at the -RSTI and -RSTO circuit to see what the hell I was doing but I remember I had problems with it. Will keep you posted.
Best Regards Ian Hughes ( carronjack )
P.S. your code looks fine but if using the EC part the Transparent Translation Registers are all zero i.e. no mmu
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Sun Jun 04, 2017 3:39 pm |
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carronjack
Joined: Mon May 22, 2017 12:11 am Posts: 23 Location: NW Scotland
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Found some more stuff, following signals all pulled up via 1K resistor pack -BGR,-TEA,-BB,-BR,-TR,-TA,-ILP0,-IlP1,-ILP2 next 1K resistor pack -TIP,-TRA,-TS,-BTT,-CLA,-SNOOP seem to remember had trouble when -BR was floating, 060 was waiting for an external bus master. FOREVER!! In answer to your last, no never had it free running, just checked and checked connections, and my old 68000 system monitor came up first time. Used AS assembler it doesn't support the 060, but if you define as one of the first lines as PROC = 68040 its as near as dammit and you can use DC.W for writing to the regs not in the 040 If you can see light at the end of the tunnel order more tunnel
Best Regards Ian Hughes ( carronjack )
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Sun Jun 04, 2017 7:34 pm |
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mercury0x000d
Joined: Tue Jun 03, 2014 2:40 pm Posts: 127
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carronjack wrote: Right found my 060 circuit diagrams in my very cluttered shed TDI and TDS tied together up to Vcc via 1K resistor. -TRST TCK -JTAG put to GND - in front of the signal says it's active low. That will stop it going into boundry scan. I need to look at the -RSTI and -RSTO circuit to see what the hell I was doing but I remember I had problems with it. Will keep you posted.
Best Regards Ian Hughes ( carronjack )
P.S. your code looks fine but if using the EC part the Transparent Translation Registers are all zero i.e. no mmu Thank you! Yes, most the 68060s I find for sale are EC models, so that'll be good. carronjack wrote: Found some more stuff, following signals all pulled up via 1K resistor pack -BGR,-TEA,-BB,-BR,-TR,-TA,-ILP0,-IlP1,-ILP2 Good to know, I'll add these assignments to my list. carronjack wrote: next 1K resistor pack -TIP,-TRA,-TS,-BTT,-CLA,-SNOOP Do these get tied high or low? carronjack wrote: seem to remember had trouble when -BR was floating, 060 was waiting for an external bus master. FOREVER!! In answer to your last, no never had it free running, just checked and checked connections, and my old 68000 system monitor came up first time. Used AS assembler it doesn't support the 060, but if you define as one of the first lines as PROC = 68040 its as near as dammit and you can use DC.W for writing to the regs not in the 040 So the 68060 was running an unmodified 68000 monitor? Nice! Would you happen to have a copy of this monitor lying about? Or know of a better one I can find somewhere? carronjack wrote: If you can see light at the end of the tunnel order more tunnel
Best Regards Ian Hughes ( carronjack ) More tunnel it is! I love it! ![Laughing :lol:](./images/smilies/icon_lol.gif)
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Mon Jun 05, 2017 12:43 am |
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Dr Jefyll
Joined: Tue Jan 15, 2013 5:43 am Posts: 189
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carronjack wrote: Mc/s = Mhz Yes; thanks, Ian, and welcome. In case anyone's wondering, c/s (or cps) means cycles per second. This self-descriptive unit got a new name ("Hertz") in the 1960's as I recall, but it still means cycles per second. And Mcps means MHz. cheers Jeff
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Mon Jun 05, 2017 2:23 am |
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carronjack
Joined: Mon May 22, 2017 12:11 am Posts: 23 Location: NW Scotland
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Without looking at the 400+ page 060 manual,which I will do again -RSTI is the reset to to the 060 -RST0 becomes active after 512 clock cyles to reset external devices. Yes in answer 2nd resistor pack all tied to 3.3V I will find a copy of my quick and dirty 68K monitor for you and post it here! If I can ever work out this internet of everything Also find a copy of my very quick subroutine threaded FORTH for 060 and ported to COLDFIRE No I'm telling porkies, it was painfully tranposed over many weeks, by brute force and ignorance. use CFASM excellent and freeware.
Best regards Ian Hughes ( carronjack )
I worked on core store 32K ( huge) look it up
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Mon Jun 05, 2017 4:27 am |
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BigEd
Joined: Wed Jan 09, 2013 6:54 pm Posts: 1783
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> Currently running a Coldfire MCF5208 @ 200Mc/s, that's how old I am, don't use hertz. > I worked on core store 32K ( huge) look it up Excellent - welcome! I've seen a core store up close, but never worked on one.
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Mon Jun 05, 2017 3:54 pm |
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carronjack
Joined: Mon May 22, 2017 12:11 am Posts: 23 Location: NW Scotland
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As I remember it was on a DEC system PDP either an 11/03 or 11/23, the magnetic rings never went wrong it was always the X,Y, or sense transistors which were BFY51's which were driving 1 amp plus which was borderline according to transistor specs Remember Towers International Transistor Selector?
Best Regards Ian Hughes ( carronjack )
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Mon Jun 05, 2017 4:59 pm |
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BigEd
Joined: Wed Jan 09, 2013 6:54 pm Posts: 1783
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> Remember Towers International Transistor Selector? Afraid not - either before my time, or not my area. I got into chip design about 1984, that was my start. Since then I've developed a progressively greater interest in the history of computers and computation, and taken to visiting museums like the one in Cambridge and the one on Bletchley Park.
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Mon Jun 05, 2017 5:10 pm |
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carronjack
Joined: Mon May 22, 2017 12:11 am Posts: 23 Location: NW Scotland
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Yes know of it, but never been it's a long way from the wilds of Scotland But my mate also ex engineer, helped rebuild/restore the ELLIOT 603 ( GEC ). He had some old hardware in his loft, and a complete bootloader on paper tape. I know it's sort of before your time, but we were still using paper tape and ASR33 teletypes in 1988. Best Regards Ian Hughes ( carronjack )
Definitions :- Turnaround time The time between feeding punched cards into an IBM 1200 card reader and getting back the remains.
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Tue Jun 06, 2017 8:36 pm |
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mercury0x000d
Joined: Tue Jun 03, 2014 2:40 pm Posts: 127
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carronjack wrote: ... Currently running a Coldfire MCF5208 @ 200Mc/s ... In what? A homebrew?
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Tue Jun 13, 2017 7:40 am |
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