Kaiser chips KS204/KS203/KS202 + kaiser boards

Discuss hardware-related topics, such as development cartridges, CopyNES, PowerPak, EPROMs, or whatever.

Moderators: B00daW, Moderators

User avatar
zoinknoise
Posts: 29
Joined: Fri Mar 04, 2016 9:43 am
Location: Ice Cream Island

Re: Kaiser chips KS204/KS203/KS202 + kaiser boards

Post by zoinknoise » Mon Jul 27, 2020 12:25 pm

hey krzysiobal have you seen this PCB yet? mapper 305

KS-7031: "Devil Town II" (aka Castlevania II FDS)
IMG_2990.jpg
IMG_2991.jpg
IMG_2988.jpg
IMG_2989.jpg
IMG_2993.jpg

lidnariq
Posts: 9491
Joined: Sun Apr 13, 2008 11:12 am
Location: Seattle

Re: Kaiser chips KS204/KS203/KS202 + kaiser boards

Post by lidnariq » Mon Jul 27, 2020 12:56 pm

... Well, I see why the description on the wiki says that the fixed banks are in reversed order. Because the 74'89s are have inverting outputs, so when the CPU wrote 0, the outputs become 255, while the CPU's address bus isn't also inverted.

That said, I'm surprised they're using 74'89s instead of 74'670s, given that they only need four banks, not more. I suppose they were cheaper.

(Parts visible in photo:
[Texas Instruments] SN7489N J340B2
[Texas Instruments] SN7489N J332B2
GoldStar GD74LS157 G50 (x2)
GoldStar GD74LS10 G30
GoldStar GD74LS02 G52
Vitelec V62C64F15L JAPAN 7A28 8708
KS128 JAPAN 821 321BPD64 DIP28
PCB component-side: "KS-7031"
PCB solder side: "8805" and some logo in an oval)

User avatar
zoinknoise
Posts: 29
Joined: Fri Mar 04, 2016 9:43 am
Location: Ice Cream Island

Re: Kaiser chips KS204/KS203/KS202 + kaiser boards

Post by zoinknoise » Mon Jul 27, 2020 8:39 pm

don't forget the resistor network! 1K right? if you look at my closeup, it's actually one pin too long for the board layout, and the last pin is just chopped off. whatever's on hand...

i can't make out the manufacturer logo, i've never seen it before. looks like it says "Start" in script font, but that is just a guess.

lidnariq
Posts: 9491
Joined: Sun Apr 13, 2008 11:12 am
Location: Seattle

Re: Kaiser chips KS204/KS203/KS202 + kaiser boards

Post by lidnariq » Mon Jul 27, 2020 10:11 pm

Right. The 7489s are not only inverting but open-collector. So it needs the resistors to convert their outputs to digital signals.

User avatar
zoinknoise
Posts: 29
Joined: Fri Mar 04, 2016 9:43 am
Location: Ice Cream Island

Re: Kaiser chips KS204/KS203/KS202 + kaiser boards

Post by zoinknoise » Mon Jul 27, 2020 10:56 pm

oh i forgot to mention my favorite part of that Devil Town II cartridge. the CHR-RAM socket. there's a 6264 already surface mounted there, which means the socket was installed afterwards. WHY?? so if the original SOIC fails, you can instantly piggyback a new working DIP part? how... thoughtful??? :shock:

this kind of madness is exactly why i collect these bootleg carts.

krzysiobal
Posts: 730
Joined: Sun Jun 12, 2011 12:06 pm
Location: Poland

Re: Kaiser chips KS204/KS203/KS202 + kaiser boards

Post by krzysiobal » Tue Jul 28, 2020 4:40 am

In fact I was searching for that game for a quite of time.
After seeing FDS Castlevania 1 port using custom KS-201 chip:
Image Image Image Image Image Image

I was expcting Devils's World 2 to use it too. Anyway, yours PCB looks quite overcomplicated:
* jumpers selecting between /ROMSEL and delayed /ROMSEL,
* whole logic for 7489's /ME (can't it be just GND? if there are already 74157 muxes)
* another delay for 7489's /WE
Just for purity, to match mapper to mask ROM memory layout, there should be one 32K bank at $8000-$ffff, pointing to last 32K in ROM and the 2k banks in $6000-$7fff should be applied with inverted bits, not vice versa.

Image Image

Could you please check if pin 8 is connected like that? I have no idea.
Image

User avatar
zoinknoise
Posts: 29
Joined: Fri Mar 04, 2016 9:43 am
Location: Ice Cream Island

Re: Kaiser chips KS204/KS203/KS202 + kaiser boards

Post by zoinknoise » Tue Jul 28, 2020 7:25 am

krzysiobal wrote:
Tue Jul 28, 2020 4:40 am
Could you please check if pin 8 is connected like that? I have no idea.
Image
yes, i just tested. pin 8 has continuity with pins 1, 5 and 6.

User avatar
Ben Boldt
Posts: 557
Joined: Tue Mar 22, 2016 8:27 pm
Location: Minnesota, USA

Re: Kaiser chips KS204/KS203/KS202 + kaiser boards

Post by Ben Boldt » Tue Jul 28, 2020 5:30 pm

zoinknoise wrote:
Mon Jul 27, 2020 10:56 pm
oh i forgot to mention my favorite part of that Devil Town II cartridge. the CHR-RAM socket. there's a 6264 already surface mounted there, which means the socket was installed afterwards. WHY?? so if the original SOIC fails, you can instantly piggyback a new working DIP part? how... thoughtful??? :shock:

this kind of madness is exactly why i collect these bootleg carts.
That is a strange one. I wonder if they just had to put "something" in there to make the thru-holes work more reliably like vias??

User avatar
zoinknoise
Posts: 29
Joined: Fri Mar 04, 2016 9:43 am
Location: Ice Cream Island

Re: Kaiser chips KS204/KS203/KS202 + kaiser boards

Post by zoinknoise » Tue Jul 28, 2020 6:03 pm

Ben Boldt wrote:
Tue Jul 28, 2020 5:30 pm
zoinknoise wrote:
Mon Jul 27, 2020 10:56 pm
oh i forgot to mention my favorite part of that Devil Town II cartridge. the CHR-RAM socket. there's a 6264 already surface mounted there, which means the socket was installed afterwards. WHY?? so if the original SOIC fails, you can instantly piggyback a new working DIP part? how... thoughtful??? :shock:

this kind of madness is exactly why i collect these bootleg carts.
That is a strange one. I wonder if they just had to put "something" in there to make the thru-holes work more reliably like vias??
nahhh you don't have to put anything in those holes. the vias on their own are fine, and then once they've gone through the wave solder they are bulletproof.

i honestly DO think that socket was installed as a precaution against a faulty SRAM chip, remember this is a bootleg cart from 1988. that 6264 would have been THE cheapest, nastiest part they could get their hands on. (it SAYS it's made by Vitelic, but who knows?)

i can imagine low-grade SRAM from 1988 not being the most reliable thing in the world.

but then that raises another question: why help with repairing the game, instead of encouraging the purchase of a whole new cartridge? to protect the dealer's reputation? to protect the Kaiser "brand"? was it because of the 1988 chip shortage that may have actually been real and not made up by Nintendo, and mask ROMs were so precious they didn't want to throw any away with a faulty cart???
is any of this real?

krzysiobal
Posts: 730
Joined: Sun Jun 12, 2011 12:06 pm
Location: Poland

Re: Kaiser chips KS204/KS203/KS202 + kaiser boards

Post by krzysiobal » Tue Jul 28, 2020 6:29 pm

If you put a chip in the socket, it wont fit in shell anymore.
I **think** that they soldered the socket as a cheap and available and fast (no need to align/bend anything) connector between the cartridge and the piggyback adapter, instead of soldering 28 wires or trying to use the thick goldpins.
i can imagine low-grade SRAM from 1988 not being the most reliable thing in the world.
Lol, this is true, when fixing tens of 168-in-1 multicarts, 80% faults were caused by broken SRAM.

User avatar
zoinknoise
Posts: 29
Joined: Fri Mar 04, 2016 9:43 am
Location: Ice Cream Island

Re: Kaiser chips KS204/KS203/KS202 + kaiser boards

Post by zoinknoise » Tue Jul 28, 2020 7:07 pm

krzysiobal wrote:
Tue Jul 28, 2020 6:29 pm
If you put a chip in the socket, it wont fit in shell anymore.
i took the thing apart...again... to see if this is true. and yes. if i put something in the socket, it won't close anymore.

and then i noticed this:
IMG_3002.jpg
i have NEVER seen this before! i completely missed it when i took the first photos. i didn't understand what krzysiobal was talking about but he TOTALLY called it.

they went to the trouble of making a tiny adapter PCB just for the SOIC chip, and they are using the socket to attach it to the cartridge board instead of regular 0.1" headers.

this either means the SOIC RAM + custom PCB was cheaper than a DIP package, or they simply could not get DIP parts that week and they hadn't redesigned this game PCB yet. so ghetto...

tepples
Posts: 22014
Joined: Sun Sep 19, 2004 11:12 pm
Location: NE Indiana, USA (NTSC)
Contact:

Re: Kaiser chips KS204/KS203/KS202 + kaiser boards

Post by tepples » Tue Jul 28, 2020 7:11 pm

The chip famine of 1988 wasn't just Nintendo posturing. It was caused by a 1986 trade deal between the United States and Japan to keep Japanese companies from selling excess chips below cost. Japanese chip makers cut production, and U.S. companies declined to increase their own production at the same time, instead (I presume) focusing on getting the next process generation up and running.

User avatar
aquasnake
Posts: 104
Joined: Fri Sep 13, 2019 11:22 pm

Re: Kaiser chips KS204/KS203/KS202 + kaiser boards

Post by aquasnake » Tue Jul 28, 2020 11:35 pm

puting two or more different packages of single chip together, its a design strategy to avoid the shortage of a certain component.

Post Reply