Bill Buckels' BMP2DHR Missing a Viewer

[Bill Chatfield]

I can't figure out how to display the DHGR files that BMP2DHR produces.
There are .A2IF files on a .DSK image, but I can't see any way to view
them. It seems kind of cruel to provide a converter without a viewer.
Haha

[I am Rob]

Do it in Applesoft

10 D$=CHR$(4)
15 ?D$”PR#3”
20 HGR:POKE49246,0:POKE49237,0:CALL62454:POKE4936,0:TEXT
25INPUT”Enter Dbl Hi-res file to view: “;NF$
30 IF NF$=“” THEN TEXT:END
40POKE49237,0: ?D$ “BLOAD “NF$”,A$2000,L$2000”
50POKE49236,0: ?D$ “BLOAD “NF$”,A$2000,L$2000,B$2000”
60 CALL -3100: GET A$: TEXT : GOTO 25

[Bill Chatfield]

Okay, that is awesome. I was actually hoping for a piece of code I
could understand rather than a binary loader.

So are the 2 BLOADs because of the AUX memory? You're switching over to
AUX memory, loading into that, and then switching back and loading into
regular memory (or the opposite). But it looks like you're loading the
same thing into both?

[TRS-90]

Well on a IIgs I would say use Super Convert 4.0

On 8-bit I would try //gif; I believe both programs were written by Jason Harper.

Matt

[qkumba]

The second BLOAD starts at offset $2000 (via B$) in the file.

[Bill Chatfield]

On Mon, 25 Dec 2023 15:51:30 -0800 (PST)
qkumba <peter....@gmail.com> wrote:

> The second BLOAD starts at offset $2000 (via B$) in the file.

I see that, but what does that result in? The AUX data starts at $2000
in the file? I don't know what the file format actually is, so I can't
make any conclusions about what it means. Thanks, though. I'm learning
a lot.

[I am Rob]

> > The second BLOAD starts at offset $2000 (via B$) in the file.
> I see that, but what does that result in? The AUX data starts at $2000
> in the file? I don't know what the file format actually is, so I can't
> make any conclusions about what it means. Thanks, though. I'm learning
> a lot.

I will just mention that we are not your teachers. There are books for that. Look for the Apple IIe Technical Reference manual.

But I will just mention that Aux memory mirrors main memory. The POKE's switch one or the other in, but only certain parts of memory. I will leave that up to you to find out which parts of memory. :)

[fadden]

On 12/26/2023 8:20 AM, Bill Chatfield wrote:
>> The second BLOAD starts at offset $2000 (via B$) in the file.
>
> I see that, but what does that result in? The AUX data starts at $2000
> in the file? I don't know what the file format actually is, so I can't
> make any conclusions about what it means. Thanks, though. I'm learning
> a lot.

FWIW, https://ciderpress2.com/doc-index.html was created to make this
sort of question easier to answer.

In this case,
https://github.com/fadden/CiderPress2/blob/main/FileConv/Gfx/DoubleHiRes-notes.md
has a list of authoritative references (//e tech note #3, file type note
$08/0000), and summarizes the standard file layout:

"Double hi-res graphics screens are generally stored as a 16KB file. The
first 8KB holds the aux RAM portion, the second 8KB holds the main RAM
portion."

The documents are stored in the CiderPress II source tree, next to the
relevant code. If something is ambiguous, you can back up one level in
the github source tree and open the converter source.

[Bill Chatfield]

On Fri, 29 Dec 2023 09:43:32 -0800
fadden <fad...@fadden.com> wrote:

> FWIW, https://ciderpress2.com/doc-index.html was created to make this
> sort of question easier to answer.
>
> In this case,
> https://github.com/fadden/CiderPress2/blob/main/FileConv/Gfx/DoubleHiRes-notes.md
> has a list of authoritative references (//e tech note #3, file type
> note $08/0000), and summarizes the standard file layout:

That is awesome! Thank you