CURRENT PROTOTYPE STATUS (SEC 64MHz 68000)

Information and news about the 68SEC000 64MHz booster.
User avatar
exxos
Site Admin
Site Admin
Posts: 23488
Joined: Wed Aug 16, 2017 11:19 pm
Location: UK
Contact:

Re: V2.5 BOOSTER CURRENT PROTOTYPE STATUS

Post by exxos »

In terms of ROM there are devices like the ST39LF801 which is 8Mbit x 16, would be ideal, but it is 3.3V :roll: so I would need level translators to use this..

There is also 5V flash SST39SF040 but 4Mbit x 8bit, so will need 2 of these.. Which I think will be easier and take less board space than adding in level translators.. But of course only enough space for 2 flash banks, not 4. But the least initially the 5V ones will be plenty get things working and tested.

Looking at SRAM, there are 5V and 3.3V of thing likes this
IS61WV5128BLL-10TLI
IS61C5128AL-10TLI

https://www.mouser.co.uk/ProductDetail/ ... A0dXGpI%3d

So either way is possible, but initially to avoid using level translators, 5V makes easy work for a prototype. Again would need two of these chips for 4Mbit. So only going to give 1MB of fast-ram, but again, this is a prototype testing so does not really matter on size. Of course this will be large enough to try ROM to SRAM copy as I was discussing earlier..

I will try and start designing new PCB for this soon....
https://www.exxosforum.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxosforum.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
User avatar
IngoQ
Site Admin
Site Admin
Posts: 1066
Joined: Tue Aug 22, 2017 8:38 am
Location: Germany

Re: V2.5 BOOSTER CURRENT PROTOTYPE STATUS

Post by IngoQ »

exxos wrote: Fri Jun 01, 2018 7:47 pm 58MHz!!! :twisted: :twisted: :twisted:
int-div from 566%(55mhz) to just shy of 600%!
Holy crap.... :shock: You really did it :excited: :yay2: :cheer:
Ingo :geek:

| Atari 1040STE@32MHz | Amiga 1200 (ACA1220) | Atari 800XL (U1MB, SIDE2) | Atari 130XL (Sophia DVI) | C64 (1541 Ultimate II, Rev3 RFMod Replacement) | TI 99/4A (F18A, 32k, FlashROM 99) | Sinclair ZX Spectrum 128 (Stereo, DivMMC) | Amstrad CPC664 (512k, M4 Wifi) | ... |
User avatar
exxos
Site Admin
Site Admin
Posts: 23488
Joined: Wed Aug 16, 2017 11:19 pm
Location: UK
Contact:

Re: V2.5 BOOSTER CURRENT PROTOTYPE STATUS

Post by exxos »

IngoQ wrote: Mon Jun 04, 2018 1:33 pm Holy crap.... :shock: You really did it :excited: :yay2: :cheer:
8-) 8-) 8-)
https://www.exxosforum.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxosforum.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
User avatar
exxos
Site Admin
Site Admin
Posts: 23488
Joined: Wed Aug 16, 2017 11:19 pm
Location: UK
Contact:

Re: V2.5 BOOSTER CURRENT PROTOTYPE STATUS

Post by exxos »

Started the schematic and rough pcb layout...

There has to be a "cut out" on the top left of the booster board (like the V2.2 booster) to avoid "hitting" the MMU.. The Flash and Fast-Ram take up a lot of space.. so god knows how more fast-ram is going to physically fit on later boards. :shrug:

sec2.png
sec2.png (83.16 KiB) Viewed 4960 times
sec2.jpg
sec2.jpg (125.23 KiB) Viewed 4960 times
https://www.exxosforum.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxosforum.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
User avatar
PhilC
Moderator
Moderator
Posts: 6012
Joined: Fri Mar 23, 2018 8:22 pm

Re: V2.5 BOOSTER CURRENT PROTOTYPE STATUS

Post by PhilC »

Looks good, can you piggy back a ram expansion board on perhaps?
If it ain't broke, test it to Destruction.
troed
Moderator
Moderator
Posts: 908
Joined: Mon Aug 21, 2017 10:27 pm

Re: V2.5 BOOSTER CURRENT PROTOTYPE STATUS

Post by troed »

IMHO it's more attractive on the STFM to overclock the MMU. While not as fast as running it directly off the CPU, it's proper ST RAM and it's an "easy" 200% boost.

FAST ROM, sure.
User avatar
exxos
Site Admin
Site Admin
Posts: 23488
Joined: Wed Aug 16, 2017 11:19 pm
Location: UK
Contact:

Re: V2.5 BOOSTER CURRENT PROTOTYPE STATUS

Post by exxos »

Forgottenmyname wrote: Wed Jun 06, 2018 9:39 am Looks good, can you piggy back a ram expansion board on perhaps?
Possible it might have to be done like that.

troed wrote: Wed Jun 06, 2018 9:45 am IMHO it's more attractive on the STFM to overclock the MMU. While not as fast as running it directly off the CPU, it's proper ST RAM and it's an "easy" 200% boost.

FAST ROM, sure.
But its not easy because its not stable ;) and with all the mods like new RAM etc, most people won't be able to do it. I even got loads of SMT MMU's to do just that, but as you know, I want to move to FPGA MMU and clock it at the same speed as the CPU and include SRAM on board. Though as this will take the next year to do.. it will have to wait.

Meanwhile, the V2.2 booster has been out of stock for some time, so I really need to wrap up this booster as its successor. Fast-Ram will run over 6x faster along with ROM and the CPU.
https://www.exxosforum.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxosforum.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
troed
Moderator
Moderator
Posts: 908
Joined: Mon Aug 21, 2017 10:27 pm

Re: V2.5 BOOSTER CURRENT PROTOTYPE STATUS

Post by troed »

exxos wrote: Wed Jun 06, 2018 10:07 am Meanwhile, the V2.2 booster has been out of stock for some time, so I really need to wrap up this booster as its successor. Fast-Ram will run over 6x faster along with ROM and the CPU.
Maybe I'm misunderstanding, but adding alt-ram will require TOS 2.06 and it won't be of use for anything that doesn't support alt-ram. Or do you only intend it for shadowing TOS?
User avatar
exxos
Site Admin
Site Admin
Posts: 23488
Joined: Wed Aug 16, 2017 11:19 pm
Location: UK
Contact:

Re: V2.5 BOOSTER CURRENT PROTOTYPE STATUS

Post by exxos »

troed wrote: Wed Jun 06, 2018 12:45 pm Maybe I'm misunderstanding, but adding alt-ram will require TOS 2.06 and it won't be of use for anything that doesn't support alt-ram. Or do you only intend it for shadowing TOS?
TOS206 is needed for alt-ram, not a problem for the booster. I have no idea what use alt-ram is, but people keep nagging about it, people buy monster for alt-ram and IDE, so its half step there for now.

Problem is 10ns fast-ram is likely going to be expensive, doable for 1MB, but cost and size soon ramps up with more MB. So I may look to using 10ns sram for ROM shadow, and maybe go with 55ns for 8MB fast-ram, but limits to around 32Mhz effective speeds then.

Once I get this booster done, it can go on sale, get a few sales to fund looking into the FPGA blitter and IDE next likely.
https://www.exxosforum.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxosforum.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
User avatar
exxos
Site Admin
Site Admin
Posts: 23488
Joined: Wed Aug 16, 2017 11:19 pm
Location: UK
Contact:

Re: V2.5 BOOSTER CURRENT PROTOTYPE STATUS

Post by exxos »

I have been looking at options for flash and ROM...

Basically 55ns 8Mb 3.3V is the only real option for the "fast ram" bank. 3.3V flash 8Mb 55ns. 2Mb 3.3V 10ns for the ROM shadow. It's the smallest and cheapest set of SRAM options. Problem is a huge bank of IO converters.. plus I have space limitations so keeping the SRAM & Flash to 1 IC is the only real option because of space limitations. I am hoping to put all the IO converts in a huge row, then branch off to the "3.3V section" above the IO row.

Routing this thing will be a nightmare and likely be a while before anymore updates for a while I do the PCB layout.
https://www.exxosforum.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxosforum.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
Post Reply

Return to “SEC 64MHZ BOOSTER”