22 Mar
2006
22 Mar
'06
7:25 p.m.
A couple of weeks ago I mentioned I'd bought a Panasonic RL-H1400
handheld computer with printer/cassette interface. I've now got a second one.
This one also came with a printer, but also with something labelled
'EPROM Extender' This is a tray that the computer fits into one side of,
and the printer into the other side. Underneath there's a PCB with 8
EPROM sockets.
The plastic housing was glued together, but I've got it apart without too
much damage. The PCB also contains 10 or so TTL chips (all
pin-through-hole), a voltage regulator, etc. I've not worked out the
details yet.
One odd thing is that these EPROM sockets, while the type that take
EPROMs in plastic carriers (i.e. they're not normal DIL sockets), are 28
pin, not the 24 pins ones in the HHC itself.
Is this the unit that would take the SNAP development ROMs?
I also have the dual-voltage (110V/240V) mains adapter (my first machine
came with the 110V-only version). This thing (for all it has 2 fuses
inside. in nice little holders) is a royal pain to dismantle. It's
assembled with 4 system-zero tamperproof screws (designed to be
impossible to remove without the right tool), down holes too small to
take the right tool. I ended up drilling out the holes slightly (8mm I
think), then using the system-zero driver to get the screws out.
It appears (but don't blame me too much if I'm wrong) that the HHC
doesn't use the NiCd pack as a shunt regulator, there's a proper
regulator circuit on the logic PCB. In which case it should be safe to
connect the adapter with the NiCd removed or defective.
-tony
23 Mar
23 Mar
8:18 a.m.
Is this the unit that would take the SNAP development
ROMs?
The SNAP ROMs came in a unit that plugs into the side of the HHC and
has sockets for four 24 pin EPROMs. Unfortunately, my SNAP ROMs no
longer work since a few of the pins broke off one of the EPROM chips
when I removed it to read the contents on my EPROM programmer. I've
purchased some machined pin sockets on someone's suggestion but I
don't seem to have the skill needed to solder the EPROM pin stubs to
the socket pins. The good news is that I *did* get images of the
EPROMs before the pins broke off this one chip.
29 Mar
29 Mar
5:36 p.m.
Is this the unit that would take the SNAP
development ROMs?
The SNAP ROMs came in a unit that plugs into the side of the HHC and
has sockets for four 24 pin EPROMs. Unfortunately, my SNAP ROMs no longer work since a few of the pins broke off one of
the EPROM chips
when I removed it to read the contents on my EPROM programmer. I've
purchased some machined pin sockets on someone's suggestion but I
don't seem to have the skill needed to solder the EPROM pin stubs to
the socket pins. The good news is that I *did* get images of the
EPROMs before the pins broke off this one chip.
Are the EPROMs a rare type? Or could you get new ones and burn the images
into them.
-tony
30 Mar
30 Mar
7:54 a.m.
Is this the unit that would take the SNAP
development ROMs?
The SNAP ROMs came in a unit that plugs into the side of the HHC and
has sockets for four 24 pin EPROMs. Unfortunately, my SNAP ROMs no
What else is in the unit? My investigations of the logic board
have shown
that there are a number of chip select lines brought out on the
expansion
connecotr, but there's no sane way to put 4 EPROMs directly on that
connector. I would guess at least there's a 2-4 line decoder. And
probably some transsitors to swich the Vcc to the EPROMs to save
battery
power (the HHC itself does that trick). These components may well
be SMD
on the back side of the board, BTW.
There are four M74LS08P chips on the board as well as the EPROMs.
I am wondering if it would be possible to make a clone of this unit,
using, say, one 16K or 32K EPROM suitable connected.
That would be a good idea. In fact, I obviously have a programmer
that can handle the chips since I was able to read their contents.
Anyone know where I can get some HN462532G chips?
I don't know enough about hardware to figure out how the unit works
myself. I guess I could send it to you if you want to take a look.
longer work since a few of the pins broke off one
of the EPROM chips
when I removed it to read the contents on my EPROM programmer. I've
purchased some machined pin sockets on someone's suggestion but I
don't seem to have the skill needed to solder the EPROM pin stubs to
the socket pins. The good news is that I *did* get images of the
EPROMs before the pins broke off this one chip.
Are the EPROMs a rare type? Or could you get new ones and burn the
images
into them.
8:05 a.m.
By the way, the part number on this SNAP extension cartridge is RL-
P9001 if that helps.
Also, I just noticed that there is another circuit board mounted
underneath the one with the EPROMs that contains lots of other chips:
M74LS22P, M74LS08P x 2, HD14002BP, M74LS00P, M74LS138P, M74LS02P,
MC14013B, MC14011B.
I guess this is more than just an EPROM expansion board.
8:29 a.m.
(I'm sorry if this message reaches the list twice. I sent it from the
wrong email address the first time.)
Right, so it's not the (3rd party) unit that I now have.
Let me ask a few questions about the SNAP development box :
What sort of EPROMs are used (how big, etc) ?
Two of the EPROMs are marked HN462532G and the other two are marked
2532JDL-45. I assume they are 32k bits (4k x 8)?
Is this the unit that would take the SNAP
development ROMs?
The SNAP ROMs came in a unit that plugs into the side of the HHC and
has sockets for four 24 pin EPROMs. Unfortunately, my SNAP ROMs no
What else is in the unit? My investigations of the logic board
have shown
that there are a number of chip select lines brought out on the
expansion
connecotr, but there's no sane way to put 4 EPROMs directly on that
connector. I would guess at least there's a 2-4 line decoder. And
probably some transsitors to swich the Vcc to the EPROMs to save
battery
power (the HHC itself does that trick). These components may well
be SMD
on the back side of the board, BTW.
There are four M74LS08P chips on the board with the EPROMs.
There is also another circuit board mounted underneath the one with
the EPROMs that contains lots of other chips: M74LS22P, M74LS08P x 2,
HD14002BP, M74LS00P, M74LS138P, M74LS02P, MC14013B, MC14011B.
I guess this is more than just an EPROM expansion board.
I am wondering if it would be possible to make a clone of this unit,
using, say, one 16K or 32K EPROM suitable connected.
That would be a good idea. In fact, I obviously have a programmer
that can handle the chips since I was able to read their contents.
Anyone know where I can get some HN462532G chips?
I don't know enough about hardware to figure out how the unit works
myself. I guess I could send it to you if you want to take a look.
By the way, the part number on this SNAP extension cartridge is RL-
P9001 if that helps.
longer work since a few of the pins broke off one
of the EPROM chips
when I removed it to read the contents on my EPROM programmer. I've
purchased some machined pin sockets on someone's suggestion but I
don't seem to have the skill needed to solder the EPROM pin stubs to
the socket pins. The good news is that I *did* get images of the
EPROMs before the pins broke off this one chip.
Are the EPROMs a rare type? Or could you get new ones and burn the
images
into them.
2:02 p.m.
What sort of EPROMs are used (how big, etc) ?
Two of the EPROMs are marked HN462532G and the other two are marked
2532JDL-45. I assume they are 32k bits (4k x 8)?
What else is in the unit? My investigations of the logic board
have shown
that there are a number of chip select lines brought out on the
expansion
connecotr, but there's no sane way to put 4 EPROMs directly on that
connector. I would guess at least there's a 2-4 line decoder. And
probably some transsitors to swich the Vcc to the EPROMs to save
battery
power (the HHC itself does that trick). These components may well
be SMD
on the back side of the board, BTW.
There are four M74LS08P chips on the board with the EPROMs.
There is also another circuit board mounted underneath the one with
the EPROMs that contains lots of other chips: M74LS22P, M74LS08P x 2,
HD14002BP, M74LS00P, M74LS138P, M74LS02P, MC14013B, MC14011B.
Ouch! A lot more logic than I was expecting (I was hoping it was just an
address decoder mapping the ROMs into one of the gaps in the HHC's memory
map). This would appera to be some kind of paging circuit (you've got a
couple of D-type flip-flops there that could be used to hold the selected
bank number).
That would be a good idea. In fact, I obviously have a programmer
that can handle the chips since I was able to read their contents.
Anyone know where I can get some HN462532G chips?
I _may_ have a couple, I will take a look...
-tony
4:04 p.m.
There is also
another circuit board mounted underneath the one with
the EPROMs that contains lots of other chips: M74LS22P, M74LS08P x 2,
HD14002BP, M74LS00P, M74LS138P, M74LS02P, MC14013B, MC14011B.
Ouch! A lot more logic than I was expecting (I was hoping it was
just an
address decoder mapping the ROMs into one of the gaps in the HHC's
memory
map). This would appera to be some kind of paging circuit (you've
got a
couple of D-type flip-flops there that could be used to hold the
selected
bank number).
5:41 p.m.
There is
also another circuit board mounted underneath the one with
the EPROMs that contains lots of other chips: M74LS22P, M74LS08P x 2,
HD14002BP, M74LS00P, M74LS138P, M74LS02P, MC14013B, MC14011B.
Ouch! A lot more logic than I was expecting (I was hoping it was
just an
address decoder mapping the ROMs into one of the gaps in the HHC's
memory
map). This would appera to be some kind of paging circuit (you've
got a
couple of D-type flip-flops there that could be used to hold the
selected
bank number). out how the code works so that it could be patched to
work in ROMS
inside the case. Anyone want to recommend a good 6502 disassembler?
The 6502 instruction set is so small that it's easy to write a
disassembler...
11:39 p.m.
I suppose I could find a 6502 disassembler and try to
figure out how
the code works so that it could be patched to work in ROMS inside the
case. Anyone want to recommend a good 6502 disassembler?
Well, I wrote a disassembler which is specifically designed for humans
to pick apart code and figure out what it does and/or how it does it.
While it doesn't support the 6502 per se, it does support a chip called
the G65SC802, which is a slight superset of the 6502; it also supports
the Tempest video game, which is actually two CPUs, one of them a
vanilla 6502 and the other the Atari vector graphics engine. Taking
the latter and ripping out (or just not using) the vector engine
support would leave you with a 6502 disassembler.
See ftp.rodents.montreal.qc.ca:/mouse/disas/src/ if you're interested.
/~\ The ASCII der Mouse
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31 Mar
31 Mar
9:53 a.m.
In article <200603310447.XAA29996 at Sparkle.Rodents.Montreal.QC.CA>,
der Mouse <mouse at rodents.montreal.qc.ca> writes:
Well, I wrote a disassembler which is specifically
designed for humans
to pick apart code and figure out what it does and/or how it does it.
What does it do besides disassembling that helps humans figure out the
code?
--
"The Direct3D Graphics Pipeline"-- code samples, sample chapter, FAQ:
<http://www.xmission.com/~legalize/book/>
Pilgrimage: Utah's annual demoparty
<http://pilgrimage.scene.org>
1:34 p.m.
Well, I wrote
a disassembler which is specifically designed for
humans to pick apart code and figure out what it does and/or how it
does it.
What does it do besides disassembling that helps humans figure out
the code? 
2:04 p.m.
In my experience, one of the best multi-platform disassemblers around is
IDA Pro:
http://www.datarescue.com/idabase/gallery/6502.htm
It's not free, but what's your time worth?
Cheers,
Chuck
3:57 p.m.
On Friday 31 March 2006 01:34 pm, der Mouse wrote:
It lets the human driving it interactively mark things as
"instruction", "8-byte number", "character string",
"pointer to memory
location", etc. The user can also define symbols (which appear in the
targets of jumps and branches when appropriate), add comments, and
suchlike. As an exmaple of the sort of thing it can produce, see
http://216.46.5.1:18804/, which is a text save straight from the
disassembler.
I used to use a product called "Dazzlestar" (named such because it used a
wordstar-like command key structure) under CP/M, which was pretty nice, but
was also usually pretty memory-limited for anything nontrivial in size. Then
there was another disassembler that I used too that I can't remember the name
of that would do a pretty good job of automatically parsing code and data
areas, you still had to make corrections but it did a lot of the work for
you.
I sure wouldn't mind finding something of the sort that would run under linux
with various target processors, for picking apart code...
Anybody know of something like that?
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
Well, I wrote a disassembler which is specifically
designed for
humans to pick apart code and figure out what it does and/or how it
does it.
What does it do besides disassembling that helps humans figure out
the code?
4:06 p.m.
On 3/31/2006 at 3:57 PM Roy J. Tellason wrote:
I sure wouldn't mind finding something of the sort
that would run under
linux with various target processors, for picking apart code...
Anybody know of something like that?
See my comment on IDA Pro. It runs on Windoze and as a Linux console app.
Cheers,
Chuck
3 Apr
3 Apr
9:05 a.m.
"Roy J. Tellason" wrote:
I sure wouldn't mind finding something of the sort that would run under linux
with various target processors, for picking apart code...
I'm probably oversimplifying, but objdump -D does a reasonable job. and
you can find gcc for most cpus (where wordsize >= 16).
objdump is part of binutils, which is part of the gnu toolchain.
I've even used it on raw binary files, by telling binutils what the cpu
and byte order was...
(not that I would ever disassemble anyone else's code. nah ah. not me. no way.)
:-)
-brad
6:32 p.m.
On Monday 03 April 2006 09:05 am, Brad Parker wrote:
"Roy J. Tellason" wrote:
Now that you mention it, I did bump into that at one point. And since then
have forgotten about it.
That's part of my problem with this stuff, I haven't spent enough time with
some of the basic tools...
I sure wouldn't mind finding something of the
sort that would run under
linux with various target processors, for picking apart code...
I'm probably oversimplifying, but objdump -D does a reasonable job. and
you can find gcc for most cpus (where wordsize >= 16).
objdump is part of binutils, which is part of the gnu toolchain. I've even used it on raw binary files, by telling
binutils what the cpu
and byte order was...
(not that I would ever disassemble anyone else's code. nah ah. not me. no
way.)
:-)
I'll have to give that a try and see what it comes up with, then.
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
6685
days inactive
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days old
16 comments
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ard＠p850ug1.demon.co.uk -
brad＠heeltoe.com -
cclist＠sydex.com -
dbetz＠xlisper.com -
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legalize＠xmission.com -
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rtellason＠blazenet.net