Mega-Cart

6502dude · Post by **6502dude** » Mon Jul 28, 2008 8:07 am

eslapion wrote:Could the Megacart benefit in any way to have a single 16 Mbit ROM instead of two 8Mbut ROMs?

No.
Decode logic for 32K ram would not work correctly with a single 16mb chip.

eslapion · Post by **eslapion** » Mon Jul 28, 2008 4:14 pm

6502dude wrote:
eslapion wrote:Could the Megacart benefit in any way to have a single 16 Mbit ROM instead of two 8Mbut ROMs?
No.
Decode logic for 32K ram would not work correctly with a single 16mb chip.

I'm sorry, I really don't see the relation.

AFAIK, if you have two 8Mbit chips on a circuit, in order to alter it to use a single 16Mbit, all you have to do is send the CS or CE lines of the two respective chips into a single AND gate then connect the output of that gate to the CE line of the 16Mbit chip then connect the CE line of the first 8MBit chip to the new higher address line of the 16Mbit chip.

Program the data from the first 8Mbit chip in the lower half of the 16Mbit chip and the data from the second 8Mbit chp into the upper half of the 16Mbit chip.

et voilà...

6502dude · Post by **6502dude** » Sat Aug 02, 2008 5:17 pm

Here is an image of MegaCart prototype #4.

The STK12C68 NVRAM chip has worked out quite nicely during testing.

Next phase is complete PAL/NTSC testing with new NVRAM chip while I finalize PCB based on SMT chips.

Mayhem · Post by **Mayhem** » Sun Aug 03, 2008 6:49 am

If any more PAL testing needs to be done, I can help out

(oh and yeah put me down for one anyhows regardless!)

nbla000 · Post by **nbla000** » Mon Aug 04, 2008 5:50 am

Mayhem wrote:If any more PAL testing needs to be done, I can help out

Tests are in good hands

I will do full MegaCart tests while Brian will work on next PCB smaller layout, i need to check new menu additional features with new chip too.

Obs1234 · Post by **Obs1234** » Sun Aug 17, 2008 1:02 pm

Any new news on the cart????

Dave

nbla000 wrote:
Mayhem wrote:If any more PAL testing needs to be done, I can help out
Tests are in good hands

I will do full MegaCart tests while Brian will work on next PCB smaller layout, i need to check new menu additional features with new chip too.

nbla000 · Post by **nbla000** » Mon Aug 18, 2008 3:50 pm

Obs1234 wrote:Any new news on the cart????

Work in progress, be patient

carlsson · Post by **carlsson** » Sat Aug 23, 2008 8:20 pm

I played with my prototype again today. I found that by inserting a bit of plastic (in my case the lid from a food container) between the underside of the cartridge and the VIC, it sits much more steady and will not keep freezing due to bad contact. The final product will have a different board layout and a real case, so that shouldn't be a matter.

Previously I had not spotted the feature "Early Menu Add", which lets you store a few favorites directly at the opening screen. By removing the default options I managed to fit up to four games without scrolling to the next page. Now if there were some options to disable the other options like normal reset and cart/tape menus, it'd be really brilliant to use on a gaming night. I imagine a settings screen could be accessed to enable the basic options.

Obs1234 · Post by **Obs1234** » Sun Aug 24, 2008 6:57 pm

If I may make a suggestion for the multi-case......

If the color of the case is not much of a cost-change, get a clear case, and maybe connect a colored LED to it so it will glow.....

Just my 2 cents....

Dave

carlsson wrote:I played with my prototype again today. I found that by inserting a bit of plastic (in my case the lid from a food container) between the underside of the cartridge and the VIC, it sits much more steady and will not keep freezing due to bad contact. The final product will have a different board layout and a real case, so that shouldn't be a matter.

Previously I had not spotted the feature "Early Menu Add", which lets you store a few favorites directly at the opening screen. By removing the default options I managed to fit up to four games without scrolling to the next page. Now if there were some options to disable the other options like normal reset and cart/tape menus, it'd be really brilliant to use on a gaming night. I imagine a settings screen could be accessed to enable the basic options.

Mikam73 · Post by **Mikam73** » Mon Aug 25, 2008 12:02 am

carlsson wrote:I played with my prototype again today.

Do you come to Back In Time Live? Wonder if it would be possible demo/show Megacart?

carlsson · Post by **carlsson** » Mon Aug 25, 2008 1:00 am

No, I am in Portugal the weekend BIT Live takes place. Besides, it would probably be terribly off-topic to demo a VIC-20 multicart at BIT Live.
Come back to Stockholm two weeks later instead and visit Retro Gathering. On that event, I will demo the MegaCart in one way or another.

nbla000 · Post by **nbla000** » Tue Aug 26, 2008 4:07 am

carlsson wrote:I played with my prototype again today. I found that by inserting a bit of plastic (in my case the lid from a food container) between the underside of the cartridge and the VIC, it sits much more steady and will not keep freezing due to bad contact. The final product will have a different board layout and a real case, so that shouldn't be a matter.

Yes Anders, please consider that you use the very first prototype version of the MegaCart, from v2 there are no problems, without case too.

Previously I had not spotted the feature "Early Menu Add", which lets you store a few favorites directly at the opening screen.

Very nice feature, i like it, i don't know wich menu revision you have btw with present version you may add up to 14 custom items on the Early Menu page, 4 in the first page and 10 in the second page (use CRS LEFT/RIGHT or F5/F7 or SPACE for next page), please consider that by adding a lot of custom item (10 or more) on the early menu, the early menu may appair with a small delay.

Now if there were some options to disable the other options like normal reset and cart/tape menus, it'd be really brilliant to use on a gaming night. I imagine a settings screen could be accessed to enable the basic options.

There isn't this option but with last menu version, like you suggested, "CARTRIDGE GAMES" and "TAPE/DISK GAMES" items are on top and by using the "KEY" selection you may select an item very quick.
Example: switch ON the vic, you see the early menu, hit Return and you enter in the Cartridge Games Menu, hit "W" and you select the first items with name starting with letter W, Witch Way in this case.

It's much more complicated to explain that to do.

This is a sample of a custum first and second page of the current Early menu:

And don't forget boot keys, with last version, by holding F1/F3/F5/F7 you select a vic configuration, VIC unexpanded / VIC+3K / VIC+32K etc etc but if you try to hold other keys....

Come back to Stockholm two weeks later instead and visit Retro Gathering. On that event, I will demo the MegaCart in one way or another.

Very nice, please remember to send us photos

carlsson · Post by **carlsson** » Tue Aug 26, 2008 5:13 am

Yes, I mean four early menu entries on the first page, and then you need to scroll to the next page. If the MegaCart is used in "kiosk mode", it could be useful to disable all the submenus and select exactly which items you want to display on the first menu screen. I'm not sure how much of a rewrite this would be, but please consider the option if possible.

nbla000 · Post by **nbla000** » Wed Aug 27, 2008 3:09 am

carlsson wrote:If the MegaCart is used in "kiosk mode", it could be useful to disable all the submenus and select exactly which items you want to display on the first menu screen.

OK i will check for a "kiosk mode" feauture, my idea still remain with MAX 14 items, 10 in the first page and 4 in the second, to not change the Early Menu Logic, the problem is only the free menu space, i've optimized a lot of things and i'm not sure if i may find space...

carlsson · Post by **carlsson** » Mon Sep 08, 2008 11:37 am

This Saturday, I accidentally dropped the MegaCart prototype from a few decimeter. Afterwards it wouldn't work properly anymore. I thought it was bust and wrote Brian about it. However tonight I applied a bit of pressure to some of the chips, and it is back to life. Even better, it appears to sit more tightly in the cartridge port now than before the drop, perhaps some weight redistributed.

Therefore, it looks like the promised demo at Retro Gathering still will be on. I'll be more careful from now on about handling it around, in particular since it is so valuable.