Date : Tue, 14 Apr 2015 23:41:04 +0200
From : laser@... (No=C3=ABlBuhagiar)
Subject: bbc-micro Digest, Vol 102, Issue 3
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Today's Topics:
1. EPROM versus ROM for BBC/B OS1.2 (No?lBuhagiar)
2. Re: EPROM versus ROM for BBC/B OS1.2 (Daniel Jameson)
3. Re: EPROM versus ROM for BBC/B OS1.2 (Peter Coghlan)
4. Re: EPROM versus ROM for BBC/B OS1.2 (Storer, Darren)
5. Re: EPROM versus ROM for BBC/B OS1.2 (Jason Flynn G7OCD)
6. Re: EPROM versus ROM for BBC/B OS1.2 (Jason Flynn G7OCD)
Message: 1
Date: Mon, 13 Apr 2015 22:28:32 +0200
From: No?lBuhagiar <laser@...>
Subject: [BBC-Micro] EPROM versus ROM for BBC/B OS1.2
To: <bbc-micro@...>
Message-ID: <4FECD47526FF417180DE4CACDEF555A4@...>
>Hi,
>I have a question maybe some of you experts here would be so kind to answer
>please, thanks.
>Can I use an EPROM instead of ROM in my BBC-B? I tried to program an EPROM
>with OS1.2 but it didn?t work.
>Why didn?t it work??
>Thanks for your help,
>Noel
http://lists.cloud9.co.uk/pipermail/bbc-micro/attachments/20150413/ac934672/attachment-0001.html
Message: 2
Date: Mon, 13 Apr 2015 21:52:11 +0100
From: Daniel Jameson <djameson@...>
Subject: Re: [BBC-Micro] EPROM versus ROM for BBC/B OS1.2
To: bbc-micro@...
Message-ID:
<CAJ_qnrxmKUijrXTb+X8FXa3tGuyO2MP+F6VgdYDXBKOYmBnuxA@...>
>Really no reason why it shouldn't work, so long as the image was correct
>and the EPROM verified ok. Problem with the beeb?
>d.
Thanks for your reply.
It didn't work and I tried about 3 images taken from different sources.
EPROM verified ok and nothing wrong with the beeb as it works fine.
n.
http://lists.cloud9.co.uk/pipermail/bbc-micro/attachments/20150413/8b91b0e1/attachment-0001.html
Message: 3
Date: Mon, 13 Apr 2015 21:51:00 +0100 (WET-DST)
From: Peter Coghlan <bbcmicro@...>
Subject: Re: [BBC-Micro] EPROM versus ROM for BBC/B OS1.2
To: bbc-micro@...
Message-ID: <01PKRYHFKQGY0077MJ@...>
>
> Can I use an EPROM instead of ROM in my BBC-B?
>
>That should work.
>
> I tried to program an EPROM with OS1.2 but it didn't work.
> Why didn't it work??
>
>Wrong type of EPROM?
(ST)M27128A (should be 16K)
>Faulty EPROM?
No it worked before with a PRINTMASTER image.
>EPROM not properly erased before programming?
Verified blank ok.
>EPROM not correctly programmed?
Program verified ok with programmer.
>EPROM not correctly inserted in correct location?
Fitted in same location were original ROM was...1st from left side.
>Jumpers set for four 4K OS EPROMs instead of one 16K EPROM?
Shouldn' be as with ROM beeb worked.
>Some incompatibility between the hardware and OS1.2?
Fitted with Data-Center, so board was modified so that 2 ROM sockets are
seen as 3 each and another for 1 RAM
if I remember correctly.
>A 27128 EPROM should be suitable. I vaguely recall reading that a 250ns
>part
i>s supposed to be required but don't quote me on that. I think I've even
had
>success with 350ns parts in the paged ROM locations at least. It should be
>possible to get various other types of EPROM to work by suitable trickery.
>If you post more details, it may be possible to provide more detailed help.
Sorry, my fault, did not send enough information as I didn't expect I would
get so much interest & help!... thanks.
>Eg, why you want to replace your OS, whether the machine worked before you
>made changes to it, whether it works again now if you reverse the changes
>and
>what exactly you mean by "didn't work" - does the machine just beep
>continuously
>and show a blank screen when you power it up or does it just show the wrong
>colours in MODE 2 or something else in between those two extremes?
>What do you get on the screen, what state are the keyboard LEDs in and can
>you
>get them to change state using the caps lock and shift lock keys?
>Regards,
>Peter Coghlan.
Just experimenting, tried putting my name instead of eg: "BBC Computer".
The machine works fine with original ROM and also tried exact OS1.2 image in
EPROM to make sure but no go.
Machine beeps continuously and shows a blank screen when powered up.
Blank.. no screen.
Did not notice state of keyboard LEDs.... will do that soon.
noel
Message: 4
Date: Mon, 13 Apr 2015 22:46:34 +0100
From: "Storer, Darren" <darren.storer@...>
Subject: Re: [BBC-Micro] EPROM versus ROM for BBC/B OS1.2
To: No?lBuhagiar <laser@...>
Cc: BBC micro mailing list <bbc-micro@...>
Message-ID:
<CAHBhi2H29y57KcCPAPKr2ovDLTC=bShqcrM8=S7S5Cp3DKV=ig@...>
>Hi Noel,
>what size of EPROM did you program? What is the part number? E.g. 27C256.
>Depending on the capacity of the EPROM (E.g. 16 k) you can sometimes cheat
>by programming an 8 k image in the top half of the EPROM too (all to do
>with address lines).
>Best regards
>Darren
Should be 16K if not mistaken... an (ST)M27128A.
Thanks for the info...
noel
On 13 April 2015@..., No?lBuhagiar <laser@...> wrote:
> Hi,
>
> I have a question maybe some of you experts here would be so kind to
> answer please, thanks.
> Can I use an EPROM instead of ROM in my BBC-B? I tried to program an EPROM
> with OS1.2 but it didn?t work.
> Why didn?t it work??
>
> Thanks for your help,
> Noel
>
> _______________________________________________
> bbc-micro mailing list
> bbc-micro@...
> http://lists.cloud9.co.uk/mailman/listinfo/bbc-micro
>
>
http://lists.cloud9.co.uk/pipermail/bbc-micro/attachments/20150413/4ba33479/attachment-0001.html
Message: 5
Date: Mon, 13 Apr 2015 23:29:04 +0100
From: Jason Flynn G7OCD <flynnjs@...>
Subject: Re: [BBC-Micro] EPROM versus ROM for BBC/B OS1.2
To: bbc-micro@...
Message-ID: <552C4330.4090205@...>
>Does this help? :
>"When replacing this with a Series 1 Operating System ROM it should
>be noted that the carrier board has rather large diameter pins, which
>sometimes damage the IC socket into which the board was fitted."
>Take from:
>http://bbc.nvg.org/doc/A%20Hardware%20Guide%20for%20the%20BBC%20Microcomputer/bbc_hw_03.htm
This is not the case... large diameter pins, no... it?s a normal EPROM with
normal pins.
On 13/04/2015 22:46, Storer, Darren wrote:
> Hi Noel,
>
> what size of EPROM did you program? What is the part number? E.g. 27C256.
>
> Depending on the capacity of the EPROM (E.g. 16 k) you can sometimes
> cheat by programming an 8 k image in the top half of the EPROM too
> (all to do with address lines).
>
> Best regards
>
> Darren
>
> On 13 April 2015@..., No?lBuhagiar <laser@...
> <mailto:laser@...>> wrote:
>
> Hi,
> I have a question maybe some of you experts here would be so kind
> to answer please, thanks.
> Can I use an EPROM instead of ROM in my BBC-B? I tried to program
> an EPROM with OS1.2 but it didn?t work.
> Why didn?t it work??
> Thanks for your help,
> Noel
>
> _______________________________________________
> bbc-micro mailing list
> bbc-micro@... <mailto:bbc-micro@...>
> http://lists.cloud9.co.uk/mailman/listinfo/bbc-micro
>
>
>
>
> _______________________________________________
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> bbc-micro@...
> http://lists.cloud9.co.uk/mailman/listinfo/bbc-micro
Message: 6
Date: Mon, 13 Apr 2015 23:32:15 +0100
From: Jason Flynn G7OCD <flynnjs@...>
Subject: Re: [BBC-Micro] EPROM versus ROM for BBC/B OS1.2
To: bbc-micro@...
Message-ID: <552C43EF.8080309@...>
>I also have a recollection of the OS ROM running at 2MHz but the SW ROMS
>only being 1MHz.
>Is your EPROM fast enough to meet 2MHz ? (although I could be
>remembering wrongly and
>don't have time to check the schematic).
Don't know about this... will try to verify if I can, thanks.
noel
On 13/04/2015 21:52, Daniel Jameson wrote:
>
> Really no reason why it shouldn't work, so long as the image was
> correct and the EPROM verified ok. Problem with the beeb?
>
> d.
>
>
>
> _______________________________________________
> bbc-micro mailing list
> bbc-micro@...
> http://lists.cloud9.co.uk/mailman/listinfo/bbc-micro
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