This is a log entry about BB-88. See the project page to know more about it.
Now that the VGA RAMDAC has been removed from the VGA signal generation circuit, I need to find a way to output the correct levels for the red, green and blue outputs. The idea …
read moreThe HP 715/80 workstation has an unusual port for input devices that requires the use of an adapter box: the HP HIL A4022-62005. This module sells at an insane price, even without its cable, so the only reasonable thing to do was to make one myself.
At the back …
read moreThis is a log entry about BB-88. See the project page to know more about it.
When I was building BB-88, it was sitting on my electronics bench, right below the roof window. And as you may suspect, it rained on it a few times, especially during summer when I …
read moreIf you've read my previous post about control hazards, you may have noticed that I talked about branches and jumps, but did not write a single word about function call or return instructions. This omission may be a bit surprising if you are not familiar with RISC-V or architectures with …
read moreI've talked about the data hazards in a previous installment, now let's talk about control hazards. A control hazard is when we need to find the destination of a jump or a branch and can't fetch any new instruction until this destination is known.
When a branch instruction is fetched …
read moreI'm currently working on the data multiplexer, the part that comes between the CPU and the memory and is responsible for putting the right byte at the right place, but I can't stop thinking about what comes next.
And let me tell you, there's still quite a lot of development …
read moreRemember that a data hazard occurs when an instruction waits for the result of a previous instruction.
In the following example:
add a0, t0, t1 ; a0 ← t0 + t1
sub a1, a0, t2 ; a1 ← a0 + t2
the add instruction stores the result into register a0 when it reaches the
Writeback stage …
I had some components to buy at Mouser for an unrelated project, but my order wasn't going to reach 50€ and I wouldn't get free shipping...
So I added a few of nearly every logic gate from the AUC family in the basket. These are like the usual 74 LS …
read moreThroughout the entire processor, there are a few basic building blocks that will be used in various places. Let's have a look at some of them.
By far, the block that we'll use the most is the register. Not only in the register file, but also between each stage …
read moreI would like to go more into detail about each stage of the pipeline, what they do and how they work. I know I said in the previous installment that I would not go into the details of hazards, but it looks like I will need it to document my …
read moreThis article is mostly a high-level overview of the Astorisc architecture, do not expect implementation tricks and gory details in here.
As I said in the presentation, I'd like to make Astorisc a pipelined processor. But what does this actually mean? I could send you to the article on Wikipedia …
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Now that BB-88 is more or less complete, let me tell you about another project
that has been on my mind for a few years now: a homebrew computer featuring a RISC-V processor made of
74 series logic.
There are already a few projects to make a RISC-V processor from …
read moreThis is a log entry about BB-88. See the project page to know more about it.
Soon after my last post about Bidule88 in 2014, I realized that four breadboards would definitely not be enough to complete the project. I quickly tore it down to restart from scratch, this time …
read moreI recently bought a Criko THD-16 drill press from 1992. It is in good general shape, except for the quill pulley bearings that get fairly noisy when I tension the belt. I thus decided to take everyhting apart, clean it thoroughly, remove the rust, and replace all the bearings. You …
read moreFor my father's 60th birthday, I made an end-grain cutting board.
It's made out of walnut and maple and took me some serious hours of work!
Pictures are here if you want to see the making of, but don't expect a real build log. Some steps are unfortunately missing.
And …
read moreToday, two parcels arrived.
The first one is a hard cover copy of The 8088 Project Book by Robert Grossblat. It seems that it is a reference on the subject, I'm eager to start reading it. Stay tuned for more Bidule88 posts in the future!
The second one is much …
read moreFirst achievement with Bidule88: it is actually running some code that I've written and uploaded into its EEPROM! Here is the result:
The parts are connected as described on Homebrew8088 except that the EEPROM I used is bigger. Not that it is needed, though, the code is only a few …
read more(Ceci est une republication d'un billet posté précédemment sur mon défunt blog)
Rien que le titre, ça donne envie, vous ne trouvez pas ?
Pour la petite histoire, c'est une recette que j'ai goûtée au café/resto le Onlywood, à Louvain-la-Neuve. J'ai tellement aimé que je me suis senti obligé d'en …
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