Loading a ROM into SW Ram - basics

discuss both original and modern hardware for the bbc micro/electron
rph
Posts: 65
Joined: Wed Jun 05, 2019 4:46 pm
Contact:

Re: Loading a ROM into SW Ram - basics

Post by rph »

Here is the version that has just the ROM (removed from .SSD then added by myself via beeb).
I'm away from beeb so can't run it to give checksum. If you can see what the difference is with the files and if it's a beebem issue.
Thanks
R
Attachments
SWRUtilTEST.ssd
(200 KiB) Downloaded 27 times
User avatar
MartinB
Posts: 5359
Joined: Mon Mar 31, 2008 10:04 pm
Location: Obscurity
Contact:

Re: Loading a ROM into SW Ram - basics

Post by MartinB »

That BASICED 'rom image' isn't a rom image - it looks like its the source code or something, possibly from github or somewhere? I can't tell how you've arrived at the file but it's just wrong! Have you selected the wrong file to download perhaps?

For example here's the first few bytes.....

Code: Select all

<!DOCTYPE html><html lang="en">  <head>    <meta charset="utf-8">  <link rel="dns-prefetch" 
href="https://github.githubassets.com">  <link rel="dns-prefetch" href="https://avatars0.githubusercontent.com">
  <link rel="dns-prefetch" href="https://avatars1.githubusercontent.com">  <link rel="dns-prefetch" href="https://avatars2.githubusercontent.com">  <link rel="dns-prefetch" href="https://avatars3.githubusercontent.com">
    <link rel="dns-prefetch" href="https://github-cloud.s3.amazonaws.com">
     <link rel="dns-prefetch" href="https://user-images.githubusercontent.com/">  
     <link crossorigin="anonymous" media="all" integrity="sha512-TD/1gdStKo77Iu1A+WNb+2YoRJv7l1hZVO0/0h+eJ5wyGxiTvIbLRko1dQ1jEa9w5BK3poi18st9OPel71zK8A==" rel="stylesheet" 
     href="https://github.githubassets.com/assets/frameworks-94d2de65a56b07e193e50e91873678b6.css" /> 
      <link crossorigin="anonymous" media="all" integrity="sha512-
User avatar
rmbrowngr
Posts: 438
Joined: Sat Jan 13, 2018 12:46 pm
Location: Dionysos, Greece
Contact:

Re: Loading a ROM into SW Ram - basics

Post by rmbrowngr »

Richard B
Acorn Electrons issue 4 and 6, MRB, Plus 1, AP6, AP5, Pegasus 400, BeebSCSI, Gotek, Raspberry Pi, GoSDC MBE.
BBC B+ 64K (128K upgraded) with Duel OS, Raspberry Pi and Gotek.
tom_seddon
Posts: 443
Joined: Tue Aug 30, 2005 12:42 am
Contact:

Re: Loading a ROM into SW Ram - basics

Post by tom_seddon »

MartinB wrote:
Mon Oct 28, 2019 6:14 pm
That BASICED 'rom image' isn't a rom image - it looks like its the source code or something, possibly from github or somewhere? I can't tell how you've arrived at the file but it's just wrong! Have you selected the wrong file to download perhaps?

For example here's the first few bytes.....

Code: Select all

<!DOCTYPE html><html lang="en">  <head>    <meta charset="utf-8">  <link rel="dns-prefetch" 
href="https://github.githubassets.com">  <link rel="dns-prefetch" href="https://avatars0.githubusercontent.com">
  <link rel="dns-prefetch" href="https://avatars1.githubusercontent.com">  <link rel="dns-prefetch" href="https://avatars2.githubusercontent.com">  <link rel="dns-prefetch" href="https://avatars3.githubusercontent.com">
    <link rel="dns-prefetch" href="https://github-cloud.s3.amazonaws.com">
     <link rel="dns-prefetch" href="https://user-images.githubusercontent.com/">  
     <link crossorigin="anonymous" media="all" integrity="sha512-TD/1gdStKo77Iu1A+WNb+2YoRJv7l1hZVO0/0h+eJ5wyGxiTvIbLRko1dQ1jEa9w5BK3poi18st9OPel71zK8A==" rel="stylesheet" 
     href="https://github.githubassets.com/assets/frameworks-94d2de65a56b07e193e50e91873678b6.css" /> 
      <link crossorigin="anonymous" media="all" integrity="sha512-
If you right click in the .rom file on the GitHub web site and do Save As, this is probably what you'll get. When you click on a file in the GitHub tree, you don't get the actual file itself, but rather an HTML page with a bunch of stuff. This makes perfect sense for the 99% of the times you're using GitHub to navigate the tree and look at text files, but it's not so much use if you're trying to download a specific binary file out of the repo...

Thanks for investigating this! It suggests I should probably rethink the release mechanism for the BASIC editor. At the very least, put ZIPs on GitHub rather than raw files, so that there's some basic consistency checking, since they won't unzip if they aren't actual .zip files.

--Tom
User avatar
jgharston
Posts: 4260
Joined: Thu Sep 24, 2009 12:22 pm
Location: Whitby/Sheffield
Contact:

Re: Loading a ROM into SW Ram - basics

Post by jgharston »

It's perfectly fine uploading binary files to GitHub. GitHub has 'Download as raw file' which will download the single raw file, and 'Download as ZIP' which will download all the files in the project as a ZIP file. But, as the above poster has discovered, you have to SELECT the link, not SaveAs the link, otherwise you save the content of the link, not the file.

Code: Select all

$ bbcbasic
PDP11 BBC BASIC IV Version 0.32
(C) Copyright J.G.Harston 1989,2005-2020
>_
User avatar
1024MAK
Posts: 10483
Joined: Mon Apr 18, 2011 5:46 pm
Location: Looking forward to summer in Somerset, UK...
Contact:

Re: Loading a ROM into SW Ram - basics

Post by 1024MAK »

Yes, that confused me when I first tried to download from GitHub. I also often check a file using a hex and ASCII file viewer / editor on the PC to make sure I have the correct file.

Mark
rph
Posts: 65
Joined: Wed Jun 05, 2019 4:46 pm
Contact:

Re: Loading a ROM into SW Ram - basics

Post by rph »

Thanks! Daft mistake.

Downloaded (correctly) and tried and all works exactly as it should.

All help appreciated guys!
rph
Posts: 65
Joined: Wed Jun 05, 2019 4:46 pm
Contact:

Re: Loading a ROM into SW Ram - basics

Post by rph »

Now I've got this working does anyone have Exmon II ROM available for download? Not been able to find.

Cheers
R
User avatar
jgharston
Posts: 4260
Joined: Thu Sep 24, 2009 12:22 pm
Location: Whitby/Sheffield
Contact:

Re: Loading a ROM into SW Ram - basics

Post by jgharston »

rph wrote:
Tue Oct 29, 2019 7:30 pm
Now I've got this working does anyone have Exmon II ROM available for download? Not been able to find.
http://mdfs.net/System/ROMs/MCode/

Code: Select all

$ bbcbasic
PDP11 BBC BASIC IV Version 0.32
(C) Copyright J.G.Harston 1989,2005-2020
>_
rph
Posts: 65
Joined: Wed Jun 05, 2019 4:46 pm
Contact:

Re: Loading a ROM into SW Ram - basics

Post by rph »

Thanks
User avatar
KenLowe
Posts: 1630
Joined: Mon Oct 18, 2004 5:35 pm
Location: UK
Contact:

Re: Loading a ROM into SW Ram - basics

Post by KenLowe »

So, I ran into the 'Illegal Address' issue again earlier today when trying to *SRSAVE a ROM to disk. This was on a beeb with DFS2.26 and SRAM 1.05. This beeb also has an APTL sideways ROM / RAM card which has 16K RAM located in bank 15. The SRAM utilities would only let me save bank 15. I got the 'Illegal Address' error if I tried to save a ROM from any other bank. Same error when trying to write to any bank other than 15 (obviously, the write would fail if trying to write to a ROM, or empty slot.

I can only conclude that SRAM 1.05 utilities checks to see if a bank is writable and if not, then it generates this error.
Post Reply

Return to “8-bit acorn hardware”