HX-34 memory upgrade

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By kansaizine

Supporter (13)

Аватар пользователя kansaizine

18-09-2010, 12:20

This machine has one TC5516AP-2 static-ram.
Does anyone know what is it installed for ?

By RetroTechie

Paragon (1563)

Аватар пользователя RetroTechie

18-09-2010, 12:32

Philips NMS8220 - no place for extra chips, but mapper is 128K with 64K RAM + 64K empty IIRC. Piggyback 2 RAM chips, add wire, done.
Because I am not a specialist of hardware, the work is very difficult for me... Tongue
Start with empty locations (IC5/IC6) first, it's just 4 pins on each. Probably corresponding pins are connected between IC5 & IC6, you can use resistance meter on low range (200 Ohms?) to confirm - a connection should show very low resistance like <1 Ohm. Most of these signals will be connected to same pins on IC3 & IC4 as well. Then you wind up with say, 5 or 6 control signals in total, and you'd have to trace those signals on the board to see where they come from (again, using resistance meter to confirm connections). When tracing back, it's possible you find some low-value resistors (~100 Ohm max) in their paths, for this purpose you can regard those as piece of circuit track... Smile2

That way you can find out what signals are used to select between 1st & 2nd 64K, and (perhaps) how those signals are generated. But please get us some pix of mainboard, that will tell general layout & what engine / custom ICs are used (if any).

By RetroTechie

Paragon (1563)

Аватар пользователя RetroTechie

18-09-2010, 12:45

TC5516 is a 2Kbyte static RAM - if machine has any built-in software (like several Sony models), that will be used to keep some data/settings.

By bluemsx

Rookie (32)

Аватар пользователя bluemsx

20-12-2012, 01:05

Hi.

Toshiba HX-34 can't be dumped by normal tools (SAVEROM.COM / MAKEROM.BAS) correctly.
A part of the firmware must be special mapper on slot 3-3.
(Firmware ROM : 80KB -- RS232C + Word Processor)

By Manuel

Ascended (18151)

Аватар пользователя Manuel

11-05-2019, 23:21

kansaizine: do you still have this machine? We now have an idea how to dump the ROM content... See https://www.msx.org/forum/msx-talk/hardware/toshiba-hx-33-or...

By popolon_

Master (163)

Аватар пользователя popolon_

23-12-2020, 17:50

Does anybody know about working toshiba hx34 memory upgrade to 128K? I have installed that additional 64K memory to empty IC sockets ( via sockets), but at least memtest.com and testram does not see more than 64k installed. But why is testram seeing main ram and megaflashrom SCC 512k ram at same 1.2 slot? Or is the mapper so special in this machine, that current software cannot even see it?
testram_hx34.md.jpg
testmem_hx34.md.jpg

I tried to check the pinout from tcx-2001 and from memory IC pins. I did not yet found any clue what could be pin(s) that shuold be shorted or pulled up to get this additional memory active (as for example in panasonic A1WX, Toshiba T9769 chip, MPSL0/1 pins). The memory pins (CAS0 and CAS1) are already connected to this tcx-2001, so only activating pin is needed.
Here are current findings for tcx-2001 pins:
1
2
3
4
5
6
7 VDP-31 CSR
8 VDP-30 CSW
9 YM2149
10 YM2149
11 D4
12 D5
13 D6
14 D7
15 GND
16 D0
17 D1
18 D2
19 D3
20
21
22
23
24
25
26
27 TCX-2002
28
29 TCX-2002
30 A0
31 A1
32 A2
33 A3
33 A4
33 A5
33 A6
33 A7
33 A8
33 A9
33 A10
41 5V
42 A11
43 A12
44 A13
45 A14
46 A15
47 RA0
48 RA1
49 RA2
50 RA3
51 RA4
52 RA5
53 RA6
54 RA7
55 RAS
56 CAS0
57 CAS1
58 TCX2002
59 TS53000P ROM- PIN 22
60 TS53000P ROM- PIN 1
61 TS53000P ROM- PIN 27
62 ALS00
63 Module port PIN 7
64 TCX2002
65 TCX2002
66 JOYSTICK?
67 JOYSTICK?
68 JOYSTICK?
69 JOYSTICK?
70 JOYSTICK?
71 JOYSTICK?
72 JOYSTICK?
73 JOYSTICK?
74 JOYSTICK?
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90 RD
91 5V
92 WR
93
94
95
96
97
98
99
100

By Manuel

Ascended (18151)

Аватар пользователя Manuel

23-12-2020, 22:14

Can you help to dump the ROM?

By msxholder

Champion (382)

Аватар пользователя msxholder

23-12-2020, 22:15

Error on Ra7 or combination a15,a14.
Page 2 no Ram and no Rom in slot 3,3

By popolon_

Master (163)

Аватар пользователя popolon_

24-12-2020, 07:46

@Manuel, Yes, I can try to dump roms. What tools are working for this hx34?

@msxholder, so is there something broken or what?

By Manuel

Ascended (18151)

Аватар пользователя Manuel

24-12-2020, 16:06

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