They are all DRAMs, either FPM, EDO or SDRAM. Think lots of pins, having to do refresh, having to do RAS, CAS and bank selection. The modules are cheap, but at a guess, even a simple adapter (without margin for distribution) would cost around $50, at least $120 with distributor margin. Not including the memory module.
Dr_Acula said...
As an aside, I've got all these old PCs lying around from 10 years ago that have 32megabyte and 64 megabyte ram modules in them. They seem to be sram type chips. And they are probably giveaways at computer stores (I've seen people make 'tech jewelry' out of them). I wonder what it would take to interface to those modules? Lots of pins, so possibly some latches, but the modules would be free...
looking at the layout image OT and the datasheet, I don't see that you've brought the CE# out to the header. If I understand this right, without it, you can't control the async mode (p.10) , nor it's various low-power modes (p.17). (Several of which would be useful if this were in a remote data logger scenario.) Or am I missing something?
I finished the layout. It took a while to get all the parts, I may add a couple of debug LEDS and one pushbutton and I have to think about the FTDI chip, if it fits I'll add it. Here is a pic of the top layer. 100x80 mm with that nice connector for expansion.
The problem is once I set a size I have to keep to it. I will see if I can economically get custom pins made. If I can then I will go with smaller size.
i think you can get the 2.54mm headers in by cheating. first and last rows only contain 2 data lines. the rest are power. You could leave off those 2 rows and use short air wires to connect the pin.
since it is a test you can get away with this. I think the 2.54mm headers will have to stay since I don't think it to reasonable with my finances at this time to try and get custom made headers at a price I can destribute.
mctrivia: I already tried to fit the connectors without luck. The size does not permit it :-(, that's why I went with a smaller connector, the separation between pins is too large to either fit on the right of the SDRAM or in between. I see of getting an adapter at least for developing purposes, do not worry. The rest of the users can better use something bigger.
Here is a way you can wire up 1 module to get you 1MB in 17pins requires 2 50cent ics. Would only take 1 more pin and 74HC573N to get the full 128MB capable from a stack of 8 Modules.
1.8V rail draws 50mA max but I would recommend a 250mA regulator because of price point and always good to have bigger then needed.
please not the pin numbers shown on the 74HC573N are wrong in the above schematic. I did not have in my library so made it up quickly with no package info.
Well, I think I finished the routing will all the components I wanted there:
FPGA, SDRAM, 2 Oscillators, VGA connector, Prop, PS/2 Connector, some debug leds, expansion connectors and so on. I'll print it tomorrow and see if the coil fits well and I'll send it to production, only 4 units.
If posible have ground plane around XTall pins and pins of PROP to XTall on both sides of PCB
Regards
ChJ
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔ Nothing is impossible, there are only different degrees of difficulty. For every stupid question there is at least one intelligent answer. Don't guess - ask instead. If you don't ask you won't know. If your gonna construct something, make it·as simple as·possible yet as versatile as posible.
Just got the ram modules in. I am still waiting for the test board so I can test if they work so it will be a bit before they are for sale but wanted to put a picture up.
This picture here is my first attempt at assembling 1. Unfortunately I did not leave the heat on long enough and the 1 IC fell off. I am going to be more careful in my next attempt.
To give an idea of scale the gold plated header on the top and bottom are 2x15 0.1" headers and the little gold dot above 8M is 2mm wide.
You can see in the top right of the picture by the modules pin 1 marker that there are 8 solder bridges. These are to select what module number the board is. I have soldered the 0 position to show that the module will be active from memory location $000000-$7FFFFF had I soldered the 1 position the module would be active from $800000-$FFFFFF. In this way up to 8 modules can be stacked vertically to give up to 64MWord or 128MBytes of RAM.
mctrivia said...
Just got the ram modules in. I am still waiting for the test board so I can test if they work so it will be a bit before they are for sale but wanted to put a picture up. ...
Looks great mctrivia. Got a header pin definition list? An Eagle library part would be nice for customers too [noparse]:)[/noparse]
as we speak i am outfitting the Gadget Gangster "RAM Expansion Module" with pogo pins so I can test them. I suspect I will have 25 for sale by monday(Modules that is I have nothing to do with the Gadget Gangster "RAM Expansion Module".
I need to find a place to buy cheap shorter pogo pins. I have these: http://www.solarbotics.com/products/pp6/ but at $0.79 each they are pretty expensive when most of my test rigs require 40 or more of them.
Comments
looking at the layout image OT and the datasheet, I don't see that you've brought the CE# out to the header. If I understand this right, without it, you can't control the async mode (p.10) , nor it's various low-power modes (p.17). (Several of which would be useful if this were in a remote data logger scenario.) Or am I missing something?
thanks
- Howard
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24 bit LCD Breakout Board coming soon. $21.99 has backlight driver and touch sensitive decoder.
I finished the layout. It took a while to get all the parts, I may add a couple of debug LEDS and one pushbutton and I have to think about the FTDI chip, if it fits I'll add it. Here is a pic of the top layer. 100x80 mm with that nice connector for expansion.
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Visit some of my articles at Propeller Wiki:
MATH on the propeller propeller.wikispaces.com/MATH
pPropQL: propeller.wikispaces.com/pPropQL
pPropQL020: propeller.wikispaces.com/pPropQL020
OMU for the pPropQL/020 propeller.wikispaces.com/OMU
I have made an eagle library that can be downloaded from propmodule.com
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24 bit LCD Breakout Board coming soon. $21.99 has backlight driver and touch sensitive decoder.
The module still has 2.54 mm headers instead of 2mm headers.
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Visit some of my articles at Propeller Wiki:
MATH on the propeller propeller.wikispaces.com/MATH
pPropQL: propeller.wikispaces.com/pPropQL
pPropQL020: propeller.wikispaces.com/pPropQL020
OMU for the pPropQL/020 propeller.wikispaces.com/OMU
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24 bit LCD Breakout Board coming soon. $21.99 has backlight driver and touch sensitive decoder.
search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=S6009-20-ND
here are for through hole
search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=S5801-20-ND
I thought your board would have the females.
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Visit some of my articles at Propeller Wiki:
MATH on the propeller propeller.wikispaces.com/MATH
pPropQL: propeller.wikispaces.com/pPropQL
pPropQL020: propeller.wikispaces.com/pPropQL020
OMU for the pPropQL/020 propeller.wikispaces.com/OMU
The 2.54 mm type are available in 30mm length which is why I chose it.
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24 bit LCD Breakout Board coming soon. $21.99 has backlight driver and touch sensitive decoder.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Visit some of my articles at Propeller Wiki:
MATH on the propeller propeller.wikispaces.com/MATH
pPropQL: propeller.wikispaces.com/pPropQL
pPropQL020: propeller.wikispaces.com/pPropQL020
OMU for the pPropQL/020 propeller.wikispaces.com/OMU
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
24 bit LCD Breakout Board coming soon. $21.99 has backlight driver and touch sensitive decoder.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Visit some of my articles at Propeller Wiki:
MATH on the propeller propeller.wikispaces.com/MATH
pPropQL: propeller.wikispaces.com/pPropQL
pPropQL020: propeller.wikispaces.com/pPropQL020
OMU for the pPropQL/020 propeller.wikispaces.com/OMU
since it is a test you can get away with this. I think the 2.54mm headers will have to stay since I don't think it to reasonable with my finances at this time to try and get custom made headers at a price I can destribute.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
24 bit LCD Breakout Board coming soon. $21.99 has backlight driver and touch sensitive decoder.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Visit some of my articles at Propeller Wiki:
MATH on the propeller propeller.wikispaces.com/MATH
pPropQL: propeller.wikispaces.com/pPropQL
pPropQL020: propeller.wikispaces.com/pPropQL020
OMU for the pPropQL/020 propeller.wikispaces.com/OMU
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
24 bit LCD Breakout Board coming soon. $21.99 has backlight driver and touch sensitive decoder.
1.8V rail draws 50mA max but I would recommend a 250mA regulator because of price point and always good to have bigger then needed.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
24 bit LCD Breakout Board coming soon. $21.99 has backlight driver and touch sensitive decoder.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
24 bit LCD Breakout Board coming soon. $21.99 has backlight driver and touch sensitive decoder.
FPGA, SDRAM, 2 Oscillators, VGA connector, Prop, PS/2 Connector, some debug leds, expansion connectors and so on. I'll print it tomorrow and see if the coil fits well and I'll send it to production, only 4 units.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Visit some of my articles at Propeller Wiki:
MATH on the propeller propeller.wikispaces.com/MATH
pPropQL: propeller.wikispaces.com/pPropQL
pPropQL020: propeller.wikispaces.com/pPropQL020
OMU for the pPropQL/020 propeller.wikispaces.com/OMU
If posible have ground plane around XTall pins and pins of PROP to XTall on both sides of PCB
Regards
ChJ
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Nothing is impossible, there are only different degrees of difficulty.
For every stupid question there is at least one intelligent answer.
Don't guess - ask instead.
If you don't ask you won't know.
If your gonna construct something, make it·as simple as·possible yet as versatile as posible.
Sapieha
Sapieha: I added in the top layer a ground plane around the crystal. Thanks
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Visit some of my articles at Propeller Wiki:
MATH on the propeller propeller.wikispaces.com/MATH
pPropQL: propeller.wikispaces.com/pPropQL
pPropQL020: propeller.wikispaces.com/pPropQL020
OMU for the pPropQL/020 propeller.wikispaces.com/OMU
This picture here is my first attempt at assembling 1. Unfortunately I did not leave the heat on long enough and the 1 IC fell off. I am going to be more careful in my next attempt.
To give an idea of scale the gold plated header on the top and bottom are 2x15 0.1" headers and the little gold dot above 8M is 2mm wide.
You can see in the top right of the picture by the modules pin 1 marker that there are 8 solder bridges. These are to select what module number the board is. I have soldered the 0 position to show that the module will be active from memory location $000000-$7FFFFF had I soldered the 1 position the module would be active from $800000-$FFFFFF. In this way up to 8 modules can be stacked vertically to give up to 64MWord or 128MBytes of RAM.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
24 bit LCD Breakout Board coming soon. $21.99 has backlight driver and touch sensitive decoder.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
24 bit LCD Breakout Board coming soon. $21.99 has backlight driver and touch sensitive decoder.
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Links to other interesting threads:
· Home of the MultiBladeProps: TriBlade,·RamBlade,·SixBlade, website
· Single Board Computer:·3 Propeller ICs·and a·TriBladeProp board (ZiCog Z80 Emulator)
· Prop Tools under Development or Completed (Index)
· Emulators: CPUs Z80 etc; Micros Altair etc;· Terminals·VT100 etc; (Index) ZiCog (Z80) , MoCog (6809)
· Search the Propeller forums·(uses advanced Google search)
My cruising website is: ·www.bluemagic.biz·· MultiBladeProp is: www.bluemagic.biz/cluso.htm
direct link
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24 bit LCD Breakout Board coming soon. $21.99 has backlight driver and touch sensitive decoder.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
24 bit LCD Breakout Board coming soon. $21.99 has backlight driver and touch sensitive decoder.
I need to find a place to buy cheap shorter pogo pins. I have these: http://www.solarbotics.com/products/pp6/ but at $0.79 each they are pretty expensive when most of my test rigs require 40 or more of them.
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24 bit LCD Breakout Board now in. $21.99 has backlight driver and touch sensitive decoder.
I wouldn't say you had nothing to do with the RAM Expansion Module - you did do the layout, which is nice and clean.
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