DIY RAM EXPANSION
Re: DIY RAM EXPANSION
Toby, Brane, Dave, Mac, ... and All,
Guess what, it works now
Measuring all tracks by voltmeter, revealed a loose address line A10, resoldering on the connector side did it.
RAM test after boot really takes a while, slightly longer compared to unexpanded QL.
As I also put TK2 on CARE cartrige EPROM.
PRINT FREE_MEM gives
600064
But this value then slighly varies, after doing some BASIC, DIR, NEW, etc.
e.g. 599552
TCAT
Guess what, it works now
Measuring all tracks by voltmeter, revealed a loose address line A10, resoldering on the connector side did it.
RAM test after boot really takes a while, slightly longer compared to unexpanded QL.
As I also put TK2 on CARE cartrige EPROM.
PRINT FREE_MEM gives
600064
But this value then slighly varies, after doing some BASIC, DIR, NEW, etc.
e.g. 599552
TCAT
Re: DIY RAM EXPANSION
Hi All,
I have a new observation, I have seen this code provided by Tobias in another thread pertaining to RAM performance.
It completes in 17 seconds, not sure, is it actually a good result?
Many thanks so far.
TCAT
I have a new observation, I have seen this code provided by Tobias in another thread pertaining to RAM performance.
Code: Select all
100 ram=RESPR(16): RESTORE 140
110 FOR p=ram TO ram+14 STEP 2: READ x: POKE_W p,x
125 t=DATE: CALL ram
130 PRINT "Test complete in ";DATE-t;" seconds."
140 DATA 28771,29439,20937,-2,20936,-8,28672,20085
Many thanks so far.
TCAT
Last edited by tcat on Sat May 17, 2014 5:56 pm, edited 1 time in total.
Re: DIY RAM EXPANSION
TCAT,
that's about the fastest you can expect for 0 wait state uncontended RAM on the QL (same speed as ROM access) - See here for some comparison figures:
http://www.qlforum.co.uk/viewtopic.php? ... urbo#p6785
Congratulations!
Tobias
that's about the fastest you can expect for 0 wait state uncontended RAM on the QL (same speed as ROM access) - See here for some comparison figures:
http://www.qlforum.co.uk/viewtopic.php? ... urbo#p6785
Congratulations!
Tobias
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Re: DIY RAM EXPANSION
Well done TCAT
Good to see it is working well
Mark
Good to see it is working well
Mark
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“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer in Somerset later in the year
QL, Falcon, Atari 520STFM, Atari 1040STE, more PC's than I care to count and an assortment of 8 bit micros (Sinclair and Acorn)(nearly forgot the Psion's)
Re: DIY RAM EXPANSION
Hi All,
I am sharing back my work as you helped me with it.
It is not perfect, yet functional on my QL.
Soldering is required from both sides, not all pads need to be connected, and there are three vias.
I used therefore straight DIN connector, as this also appears easier to solder with a common non professional iron I have got.
I bent inner connector pins to an angle by tweezers and outer ones left straight, making connections with small lenghts of wire.
Many thanks
Tom
I am sharing back my work as you helped me with it.
It is not perfect, yet functional on my QL.
Soldering is required from both sides, not all pads need to be connected, and there are three vias.
I used therefore straight DIN connector, as this also appears easier to solder with a common non professional iron I have got.
I bent inner connector pins to an angle by tweezers and outer ones left straight, making connections with small lenghts of wire.
Many thanks
Tom
- eeschema (2010-03-14)-final >> Creation date: Thu 24 Apr 2014 07:33:24 PM CEST
#Cmp ( order = Reference )
| C1 0.33uF
| C2 0.1uF
| C3 100uF/10V
| C4 0.33uF
| C5 0.33uF
| IC1 AS6C4008-55PCN
| IC2 GAL16V8
| P1 C64AB_FEMALE
| U1 LM7805
#End Cmp
#Cmp ( order = Value )
| 0.1uF C2
| 0.33uF C1
| 0.33uF C4
| 0.33uF C5
| 100uF/10V C3
| AS6C4008-55PCN IC1
| C64AB_FEMALE P1
| GAL16V8 IC2
| LM7805 U1
#End Cmp
#End List
Last edited by tcat on Thu May 22, 2014 7:53 pm, edited 1 time in total.
Re: DIY RAM EXPANSION
Thanks for publishing this, tcat.
You might want to add your JEDEC for the GAL you used, and a list of parts. This would then be a complete package anyone could put together. Also, by publishing your JEDEC and algorithm people can maybe modify it and feed back into your project.
If people are interested in building this, I have the majority of the parts (not the PCB or DIP version of the RAM though) and if tcat is interested, I'd be happy to put a kit together for those who want to make their own PCBs.
You might want to add your JEDEC for the GAL you used, and a list of parts. This would then be a complete package anyone could put together. Also, by publishing your JEDEC and algorithm people can maybe modify it and feed back into your project.
If people are interested in building this, I have the majority of the parts (not the PCB or DIP version of the RAM though) and if tcat is interested, I'd be happy to put a kit together for those who want to make their own PCBs.
Re: DIY RAM EXPANSION
Don´t forget to offer fully populated boards for people that can only replace a capacitor on a Spectrum, like me
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Re: DIY RAM EXPANSION
Hi,
I was going to make a PCB for myself.
Would there be a demand for more?
I was going to make a PCB for myself.
Would there be a demand for more?
Regards,
Derek
Derek
Re: DIY RAM EXPANSION
I guess this depends on when Dave will be able to deliver his RAM, and on your price