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Free 68000 ICs to Good Home.

Posted: Sat Jan 19, 2019 10:11 am
by lezanderson
Hi.

Free to Good Home.

I've got some surplus 68000 ICs and stuff... if anyone wants them for Retrobrew projects etc then just email me.

(Note 68000 ICs are in PLCC package):

68HC000FNxx PLCC68 1pcs
68010FNxx PLCC68 1pcs
68008FNxx PLCC52 1pcs
68901 PLCC 1pcs
68230 PLCC 1pcs
68881 FPU PLCC 1pcs
512K SRAM DIP 2pcs
64K EEPROM DIP 2pcs
uPD72020 VDP vdieo Chip (non QL) DIP40 1pcs
DS12887 RTC DIP 1pcs
SAA1099 Sound Chip DIP 1pcs

Also Got some other stuff old NMOS 6502s,Z80s etc

Just email me at lezanderson@gmail.com

* First come first served >>

Re: Free 68000 ICs to Good Home.

Posted: Sat Jan 19, 2019 4:21 pm
by martyn_hill
Hi Lez

I've just emailed you - but might have missed the boat :-)

Martyn.

Re: Free 68000 ICs to Good Home.

Posted: Mon Jan 21, 2019 3:48 pm
by lezanderson
All Gone !!

The ICs have now all gone (or will) be going to a good home.

Re: Free 68000 ICs to Good Home.

Posted: Mon Feb 25, 2019 3:12 pm
by lezanderson
** More FREE ICs... to Good Home !!


Are you Building a Homebrew Sinclair QL?

If anyone is interested in design and building their own Sinclair QL ( or is already doing so) Then I can offer FREE ICs.


I have Integrated Circuits (ICs) like :

MC68008Pxx DIP48
MC68901 MFU
MC68230 SIO
MC68681 PIO
512K SRAM, 128K SRAM,128K EPROM 64K EPROM , Fast SRAM (IS6C1024-10 10ns) etc
*CPLDs: EPM7512xxx,EPM7128SLC84, EPM7256AETxx (BLANK) etc
*GAL16v8,GAL20V8,GAL22V10 (BLANK)
LM1889, MC1377P PAL/NTSC TV Encoders
DS12887 RTC
AM9511 Maths Co-processor
8051 ,AT89C2051 Atmeg, etc MCUs
DS1250 512k Non Volatile Static RAM (Can be used as Silicon Disc).
SAA1099,SN76489,YM2149,AY-3-8910 Sound Chips DIP
MAX705 IC Supervisor/RESET DIP
MAX232 RS232 Drivers DIP
74HC138,74HC139,74HC154 Decoders (<3 to 8>, 2< to 4>,< 4 to 16>)
6502/6800 stuff like : 68B21,68B50,6522,HD63C09 etc
MB8877,WD1772,uPD765 etc FDCs (Floppy Disc Controllers)
7805 Regulators

& CPLDS /GALs are Blank and would need programming.

Obviously I can only dish out stuff to those that are serious, otherwise I'd just be sending chips to people that may never use then !

Email me at lezanderson@gmail.com

Re: Free 68000 ICs to Good Home.

Posted: Mon Feb 25, 2019 3:58 pm
by Dave
That's a nice list. :)

There's a couple of specific items I'd be grateful for. Would you be interested if I paid shipping to Texas, USA?

The GALs and the 1772s.

Sorry, couldn't handle the British weather any more and quit ;)

Re: Free 68000 ICs to Good Home.

Posted: Thu Feb 28, 2019 9:55 am
by lezanderson
Dave wrote:That's a nice list. :)

There's a couple of specific items I'd be grateful for. Would you be interested if I paid shipping to Texas, USA?

The GALs and the 1772s.

Sorry, couldn't handle the British weather any more and quit ;)
I may only have WD1773s left..I'll have to check. I believe these have the Data separator built into the one chip.

Re: Free 68000 ICs to Good Home.

Posted: Thu Feb 28, 2019 9:56 am
by lezanderson
Best to email me if you want any of the ICs as I don't check the forum everyday, just occasionally.

Re: Free 68000 ICs to Good Home.

Posted: Thu Feb 28, 2019 9:58 am
by lezanderson
Thoughts and ideas on designing and building a Homebrew QL

My thoughts and musings on the design and possible building of a DIY / homebrew Sinclair QL

Specification:

68008 CPU (HD/MC68008P12) 12Mhz Max.
512K SRAM or more
64K,128K EPROM
CPLD to emulate ZX8301,ZX8302
Modern MCU to do functions of 8049 including Handling Microdrives
Proper Sound via Sound Chip/Chips: Programmable sound generators PSG. AY-3-89xx,SN76489,SAA1099 etc
Extra I/O via ICs like MC68901,68230,68681 etc
WDC1773 Floppy disc functionality… thou this may be rather obsolete ?
SD Card via PIO connectivity.
Real time Clock & Calendar for Time Date: DS12887/DS1310 etc
Maths Co-processor : Generic AM9511-4DC 4MHz FPU
PS/2 Keyboard mouse functionality via a MCU (AT89C2051 etc).
Silicon disc ? (DS1250 512K NVSRAM)
Voltage Regulator to supply +12V, +5V to Board.

Design Method :

A real 68008 CPU DIP48 would be at the heart of the system, clock speed Max 12MHz. RAM would be SRAM > 512K+128K(Fast SRAM). Memory Decoding could be done via a GAL/CPLD or a 74HC Decoder , 74HC138,74HC154 etc. I/O Decoding could be done by a GAL. Alternatively Memory/I/O functions could be incorporated into a large CPLD to save on the number of chips used.
The Functions of the ZX8301/ZX8302 would need to be incorporated into large CPLDs so they could emulate these ULAs functionality.
A MCU (Micro-controller unit) would be used to do the work of the 8049.
Extra I/O functions could be achieved via powerful chips like 68901 MFU.
Extra Storage can be done via SD Card or PATA Harddrive using Parallel ports. I’ve seen this done using chips like the Intel 8255 PIO. NVSRAM could be used to give Silicon Disc Storage using chips like DS1250 512K Non-Volatile Static RAM.
P2S/2 keyboard / Mouse could be implemented to be used rather than the original QL Keyboard.

Adding proper Sound Chips.
By using low cost legacy sound chips like the YM2149/AY-3-8910, SN76489, & Phillips SAA1099 Sound Generators, the QL could have proper sound capabilities. To use all three would need summing amplifiers to mix the individual sound outputs to produce stereo LEFT and RIGHT sound outputs.

I/O Sockets: Where possible the original D-type sockets etc would be used . The power supply could be via a simple Jack socket. The TV modulator would no longer be necessary and this could be replaced with a SCART connector or Phono jacks for TV & Sound. Micro drives controlled in the same way via Micro controller Unit (MCU), but with SD card storage micro drives would be redundant.

Floppy Disc Controller ?
WDC1773 FDC Floppy Disc controller with inbuilt Data-Separator.
For anyone wanting a Floppy disc interface you could use a chip like a WD1773 (WD1770 derivative). Though these days having a Floppy interface maybe somewhat unnecessary.

A low cost +12 to 15V Switch mode Power supply would be converted to +12V & +5V for the circuit board.


Complex Programmable logic to Emulate ULAs.
Altera MAX EPM7512ART144 to emulate a Sinclair QL ZX8301 ULA?
With 512 Macrocells an EPM7512 could be programmed to emulate the functionality of the QLs video and timing chip (ZX8301). With superfast SRAM (IS61C1024-10: 128k x 8bit,10ns,DIP32,) being used as Pseudo Dual Port SRAM for both User RAM and Video RAM. This is possible because in say a 70ns Memory access ‘Window’ the 128K Fast SRAM, can be accessed by both the CPU and Video logic, as long as they both use the same master clock, so everything is synchronised. The digital video output from the CPLD would be converted to analogue RGB, HYSNC, VSYNC via DACs and then fed into a TV encoder like a MC1377 or LM1889 to give composite TV output.
Theoretically the CPLD would produce the QLs original video displays plus some extra. Also provide timing from a master clock for video and Pseudo Dual Port SRAM.
You could use real Dual Port SRAMs like the IDT7008 (64k s 8bit), but these are rather expensive.
Using Dual Port SRAM (or Pseudo ) would allow the CPU, 68008 to access Video RAM at any time, so the Video logic would not slowdown the CPU when drawing the Raster Display. Allowing the 68008 to run at full speed all the time! At 12MHz this would make it approximately 2.5 times faster than the original QL.

The ZX8302 could possibly be implemented using a smaller Macrocell size CPLD like the EPM7128SLC84 giving the I/O function of this chip.

Costing :

Something that is often overlooked at the design stage of a build is costing. If you do this, then you could end up designing a system that is simply unrealistic, due to cost, to build. Also try using commonly available components that can be readily sourced.

One rule of thumb is to assume the cost of the final system will be made up of, One Third for the price of the ICs, One Third for the PCB and One Third for miscellaneous things like Resistors, Capacitors, switches, Power Jack, D-Type connectors, IC Sockets etc

MC68008P12 DIP48………………...….. $2.50
512K SRAM DIP32 ……………...…........$3.50
IS6C1024-10 SDIP32…………….…….......$1.0
27C1001-45 128K EPROM ……….…..….$1.0
W27C512-45 64K EEPROM……….…......$1.0
EPM7512AET144 etc CPLD ……….…....$15.0 *
EPM7256AETxx etc CPLD……….…..…..$8.0 *
EPM7128SLC84-15 CPLD …………...…..$1.50
89C51 etc MCU…………………….…..….$0.50
AT89C2051 MCU………………….….….$0.50
7805,7905,7812 Regulators...……………...$1.50

Optional :
MC68901 MFU DIP………………...…... $2.50
MC68230 I/O Chip DIP…..……………....$2.50
MC68681 I/O DIP…………..….…….......$2.50
DS12887 RTC………………………..……..$2.0
AM9511-xx FPU…………………….……..$2.0
YM2149 Sound Chip……………….…..…..$1.50
SN76489 Sound Chip………………..…….$0.50
SAA1099 Sound Chip………………..…….$2.0
WD1773 FDC………………………….…...$2.50
DS1250 512K (NVSRAM)………….……..$2.50

* Ignore Crazy eBay prices especially for things like the EPM7512 CPLD !

Total for ICs approx $50 about £40

So the Total build should be (at a guestimate) £120

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Though this is clearly a simplistic view, it still gives a good starting point for someone thinking of undertaking the task of design and building a homebrew microcomputer

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Re: Free 68000 ICs to Good Home.

Posted: Thu Feb 28, 2019 7:44 pm
by Whopper
lezanderson wrote:Thoughts and ideas on designing and building a Homebrew QL
And the PCB?

Re: Free 68000 ICs to Good Home.

Posted: Thu Feb 28, 2019 10:58 pm
by Dave
If you can do all that stuff you said, I'll do the PCB.