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Vintage Computers Any vintage computer systems, calculators, video games etc., but with an emphasis on 1980s and earlier equipment. |
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21st Mar 2018, 11:46 pm | #1 |
Nonode
Join Date: May 2007
Location: Redruth, Cornwall, UK.
Posts: 2,573
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Interpreting a hexdump table
Hi
For sometime now I've been wanting to do some experiments with EPROM ICs and in particular, there was a project in Elektor Electronics called Elabyrinth, a sort of electronic maze game. Having had next to no experience with EPROMs my difficulty is understanding the contents of a hexdump. The relevant hexdump is shown in the attached pic. I am not asking for detailed information on the actual program rather the principles of how the data is entered to the programmer. I need to understand what the relevant fields mean in terms of address and data. In simple terms how would I interpret the entries in the table in order to program the EPROM? I've not been able to find a good explanation of what each of the fields in the table mean and how to transfer this to the programmer. Sorry for such basic questions but as you can tell I'm not experienced in this field. The EPROM is a 2716. I have a Stag PP28 EPROM programmer and a UV EPROM eraser as well. Any help would be much appreciated. Thanks. Regards Symon |
22nd Mar 2018, 12:09 am | #2 |
Dekatron
Join Date: Jun 2009
Location: Staffordshire Moorlands, UK.
Posts: 5,271
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Re: Interpreting a hexdump table
they look like a simple memory dump to me. The first figure on the left is the address and the numbers that follow are the values in address (+0), address +1, address +2 etc to the end, and then onto the next new row which is another address followed by the bytes in consecutive addresses as before.
If you see what I mean. Do you have the dump in a useable format or have you got to type in all those values by hand?
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Kevin |
22nd Mar 2018, 12:23 am | #3 |
Nonode
Join Date: May 2007
Location: Redruth, Cornwall, UK.
Posts: 2,573
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Re: Interpreting a hexdump table
Hi Kevin
Thanks for explaining that. The only hexdump I have is the one in the previously attached pic, ideally a hexfile would make things easier so in it's absence, it seems the data has to be entered manually, a laborious task and probably prone to error. I'll try to familiarise myself with the programmer to contemplate the program sequence. Regards Symon. |
22nd Mar 2018, 12:27 am | #4 |
Dekatron
Join Date: Aug 2003
Location: near Reading (and sometimes Torquay)
Posts: 3,094
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Re: Interpreting a hexdump table
You need to find out what data format your programmer accepts. A typical one is described here: https://en.wikipedia.org/wiki/Intel_HEX
If that is what the programmer wants then you need a small program to convert it as working out the sumchecks is a bit tedious by hand. |
22nd Mar 2018, 12:28 am | #5 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,944
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Re: Interpreting a hexdump table
You may be able to scan the printout and use OCR software to turn it into ASCII text. You would need to check carefully for OCR errors, but this would still be easier than typing it all in. You would then need to write a bit of code to turn the ASCII representation into binary data - easy enough to do if you have any experience with C or Pascal.
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22nd Mar 2018, 12:38 am | #6 |
Nonode
Join Date: May 2007
Location: Redruth, Cornwall, UK.
Posts: 2,573
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Re: Interpreting a hexdump table
Hi Paul.
I like the idea of using OCR but I wish that I had the programming skills to write suitable code to convert the ASCII code to binary. That's a useful project in its own right. For the time being, I would be more than happy to program the EPROM manually. I will now be familiarising myself with the Stag programmer. Regards Symon. |
22nd Mar 2018, 12:43 am | #7 | |
Nonode
Join Date: May 2007
Location: Redruth, Cornwall, UK.
Posts: 2,573
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Re: Interpreting a hexdump table
Quote:
Regards Symon. |
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22nd Mar 2018, 12:46 am | #8 |
Hexode
Join Date: Oct 2016
Location: Newport, South Wales, UK.
Posts: 278
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Re: Interpreting a hexdump table
There are online tools to convert ASCII to binary, such as https://onlinebinarytools.com/convert-ascii-to-binary
(Example, not endorsement ). |
22nd Mar 2018, 1:25 am | #9 | |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,944
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Re: Interpreting a hexdump table
Quote:
If you can program an EEPROM then you can certainly handle the simple high level programming involved. There is plenty of example code around if you google. |
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22nd Mar 2018, 2:43 am | #10 |
Pentode
Join Date: May 2009
Location: Stockton-on-Tees, County Durham, UK.
Posts: 154
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Re: Interpreting a hexdump table
if i had a better image i could type it all in and produce many different formats for you.
the 3 digit number before the colon (at the start of each row) is the high part of the address in the eprom, the numbers across the top i.e. 0,1,2,3,4,5,6,7,8 .etc are the low part of the address. to get the address in the eprom of a particular byte look at the number at the very top of the column and add it to the number at the very left of the row (windows calculator even has a mode for this under view->programmer, just be sure to select the Hex option). however be aware that this hex dump is split into two columns of 16 bytes each
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22nd Mar 2018, 6:06 am | #11 |
Dekatron
Join Date: May 2006
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Re: Interpreting a hexdump table
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22nd Mar 2018, 7:44 am | #12 |
Nonode
Join Date: Aug 2010
Location: Resolven, Wales; and Bristol, England
Posts: 2,608
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Re: Interpreting a hexdump table
I remember typing such programs into a Sinclair MK14.... it was quite tedious but possible.
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Richard Index: recursive loop: see recursive loop |
22nd Mar 2018, 11:06 am | #13 |
Nonode
Join Date: May 2007
Location: Redruth, Cornwall, UK.
Posts: 2,573
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Re: Interpreting a hexdump table
Hi.
Please see attached part of the table. So taking the very first address, hex 0000, the 1 byte data assigned to that address is hex 1C, and in binary form would be 0001 1100. Taking address 040E (binary 0000 0100 0000 1110) the data assigned to that address is hex 09 ( binary 0000 1001). I am now understanding the format of the table and appreciate all your help so far thanks. Regards Symon. |
22nd Mar 2018, 11:29 am | #14 | |
Nonode
Join Date: Oct 2008
Location: Warsaw, Poland and Cambridge, UK
Posts: 2,677
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Re: Interpreting a hexdump table
Quote:
This reminds me of hand typing hex code in to my ZX81 in my youth. It was a notoriously error-prone process! Chris
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22nd Mar 2018, 1:09 pm | #15 |
Tetrode
Join Date: Feb 2016
Location: Guisborough, North Yorkshire, UK.
Posts: 80
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Re: Interpreting a hexdump table
Sorry to ask a silly question, but where did the hexdump come from?
Do you have a piece of software that generated it? If so, can you not re-direct the output to a file? You can then use a small prog (BASIC perfectly fine) to read the file and write the data out to make a raw binary image. Prog slightly more complicated if you need to manipulate the two column format shown in your example. Much easier than entering everything by hand? Geoff |
22nd Mar 2018, 3:41 pm | #16 | |
Nonode
Join Date: May 2007
Location: Redruth, Cornwall, UK.
Posts: 2,573
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Re: Interpreting a hexdump table
Quote:
So taking one more example to clarify, hex address 02B has hex data 59 assigned to it or binary 0101 1001. Regards Symon. |
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22nd Mar 2018, 3:46 pm | #17 |
Nonode
Join Date: May 2007
Location: Redruth, Cornwall, UK.
Posts: 2,573
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Re: Interpreting a hexdump table
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22nd Mar 2018, 3:55 pm | #18 |
Pentode
Join Date: May 2009
Location: Stockton-on-Tees, County Durham, UK.
Posts: 154
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Re: Interpreting a hexdump table
Exactly.
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If it can be built, it can also be fixed. |
22nd Mar 2018, 4:01 pm | #19 |
Nonode
Join Date: May 2007
Location: Redruth, Cornwall, UK.
Posts: 2,573
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Re: Interpreting a hexdump table
Great, thanks. I am now on track and sorry to seem such a duffer at this, I should have taken more interest in this aspect of electronics in my younger years.
Regards Symon |
22nd Mar 2018, 4:11 pm | #20 | |
Dekatron
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 11,556
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Re: Interpreting a hexdump table
Quote:
Mole42 is right about the tedium of having to type code in as hex, the only way in which 'early' single board computers could usually be programmed. Actually those were the deluxe versions, in around 1977/78 Elektor did a microprocessor teaching project (also based, like the MK14, on the INS8060 or SC/MP), which used LEDs and switches so all input and output was in binary. As a matter of interest Symon, which microprocessor does this Elektor project of yours use? |
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